diff --git a/frontend/components/global/AutoForm.vue b/frontend/components/global/AutoForm.vue
index 473131712..5bdbbbe3b 100644
--- a/frontend/components/global/AutoForm.vue
+++ b/frontend/components/global/AutoForm.vue
@@ -88,6 +88,25 @@
               validate-on="input"
             />
 
+            <!-- Number Input -->
+            <v-number-input
+              v-else-if="inputField.type === fieldTypes.NUMBER"
+              v-model="model[inputField.varName]"
+              variant="underlined"
+              :control-variant="inputField.numberInputConfig?.controlVariant"
+              density="comfortable"
+              :label="inputField.label"
+              :name="inputField.varName"
+              :min="inputField.numberInputConfig?.min"
+              :max="inputField.numberInputConfig?.max"
+              :precision="inputField.numberInputConfig?.precision"
+              :hint="inputField.hint"
+              :hide-details="!inputField.hint"
+              :persistent-hint="!!inputField.hint"
+              :rules="!(inputField.disableUpdate && updateMode) ? inputField.rules || [] : []"
+              validate-on="input"
+            />
+
             <!-- Option Select -->
             <v-select
               v-else-if="inputField.type === fieldTypes.SELECT"
diff --git a/frontend/composables/forms/use-field-types.ts b/frontend/composables/forms/use-field-types.ts
index 20ea4f380..7f1b5f81a 100644
--- a/frontend/composables/forms/use-field-types.ts
+++ b/frontend/composables/forms/use-field-types.ts
@@ -1,6 +1,7 @@
 export const fieldTypes = {
   TEXT: "text",
   TEXT_AREA: "textarea",
+  NUMBER: "number",
   SELECT: "select",
   BOOLEAN: "boolean",
   PASSWORD: "password",
diff --git a/frontend/lang/messages/en-US.json b/frontend/lang/messages/en-US.json
index 8929adc94..5e6c3d5aa 100644
--- a/frontend/lang/messages/en-US.json
+++ b/frontend/lang/messages/en-US.json
@@ -1134,7 +1134,22 @@
       "example-unit-singular": "ex: Tablespoon",
       "example-unit-plural": "ex: Tablespoons",
       "example-unit-abbreviation-singular": "ex: Tbsp",
-      "example-unit-abbreviation-plural": "ex: Tbsps"
+      "example-unit-abbreviation-plural": "ex: Tbsps",
+      "standardization": "Standardization",
+      "standardization-description": "How this unit can be represented as a standard unit. This enables unit conversion features such as merging compatible units in shopping lists.",
+      "standard-unit": "Standard Unit",
+      "standard-quantity": "Standard Quantity",
+      "unit-conversion": "Unit Conversion",
+      "standard-unit-labels": {
+        "fluid-ounce": "fluid ounce",
+        "cup": "cup",
+        "ounce": "ounce",
+        "pound": "pound",
+        "milliliter": "milliliter",
+        "liter": "liter",
+        "gram": "gram",
+        "kilogram": "kilogram"
+      }
     },
     "labels": {
       "seed-dialog-text": "Seed the database with common labels based on your local language.",
diff --git a/frontend/lib/api/types/household.ts b/frontend/lib/api/types/household.ts
index 05a0abf42..ce2b63bb6 100644
--- a/frontend/lib/api/types/household.ts
+++ b/frontend/lib/api/types/household.ts
@@ -329,6 +329,8 @@ export interface IngredientUnit {
   pluralAbbreviation?: string | null;
   useAbbreviation?: boolean;
   aliases?: IngredientUnitAlias[];
+  standardQuantity?: number | null;
+  standardUnit?: string | null;
   createdAt?: string | null;
   updatedAt?: string | null;
 }
@@ -348,6 +350,8 @@ export interface CreateIngredientUnit {
   pluralAbbreviation?: string | null;
   useAbbreviation?: boolean;
   aliases?: CreateIngredientUnitAlias[];
+  standardQuantity?: number | null;
+  standardUnit?: string | null;
 }
 export interface CreateIngredientUnitAlias {
   name: string;
diff --git a/frontend/lib/api/types/non-generated.ts b/frontend/lib/api/types/non-generated.ts
index 84f9ff7fe..752236b1f 100644
--- a/frontend/lib/api/types/non-generated.ts
+++ b/frontend/lib/api/types/non-generated.ts
@@ -58,3 +58,13 @@ export interface QueryFilterJSONPart {
   relationalOperator?: RelationalKeyword | RelationalOperator | null;
   value?: string | string[] | null;
 }
+
+export type StandardizedUnitType
+  = | "fluid_ounce"
+    | "cup"
+    | "ounce"
+    | "pound"
+    | "milliliter"
+    | "liter"
+    | "gram"
+    | "kilogram";
diff --git a/frontend/lib/api/types/recipe.ts b/frontend/lib/api/types/recipe.ts
index ca19b1d29..d869c8914 100644
--- a/frontend/lib/api/types/recipe.ts
+++ b/frontend/lib/api/types/recipe.ts
@@ -85,6 +85,8 @@ export interface CreateIngredientUnit {
   pluralAbbreviation?: string | null;
   useAbbreviation?: boolean;
   aliases?: CreateIngredientUnitAlias[];
+  standardQuantity?: number | null;
+  standardUnit?: string | null;
 }
 export interface CreateIngredientUnitAlias {
   name: string;
@@ -174,6 +176,8 @@ export interface IngredientUnit {
   pluralAbbreviation?: string | null;
   useAbbreviation?: boolean;
   aliases?: IngredientUnitAlias[];
+  standardQuantity?: number | null;
+  standardUnit?: string | null;
   createdAt?: string | null;
   updatedAt?: string | null;
 }
@@ -498,6 +502,8 @@ export interface SaveIngredientUnit {
   pluralAbbreviation?: string | null;
   useAbbreviation?: boolean;
   aliases?: CreateIngredientUnitAlias[];
+  standardQuantity?: number | null;
+  standardUnit?: string | null;
   groupId: string;
 }
 export interface ScrapeRecipe {
diff --git a/frontend/pages/group/data/units.vue b/frontend/pages/group/data/units.vue
index f522092fc..491a72d9c 100644
--- a/frontend/pages/group/data/units.vue
+++ b/frontend/pages/group/data/units.vue
@@ -158,6 +158,7 @@ import RecipeDataAliasManagerDialog from "~/components/Domain/Recipe/RecipeDataA
 import { validators } from "~/composables/use-validators";
 import { useUserApi } from "~/composables/api";
 import type { CreateIngredientUnit, IngredientUnit, IngredientUnitAlias } from "~/lib/api/types/recipe";
+import type { StandardizedUnitType } from "~/lib/api/types/non-generated";
 import { useLocales } from "~/composables/use-locales";
 import { normalizeFilter } from "~/composables/use-utils";
 import { useUnitStore } from "~/composables/store";
@@ -219,6 +220,16 @@ const tableHeaders: TableHeaders[] = [
     show: true,
     sortable: true,
   },
+  {
+    text: i18n.t("data-pages.units.standard-quantity"),
+    value: "standardQuantity",
+    show: false,
+  },
+  {
+    text: i18n.t("data-pages.units.standard-unit"),
+    value: "standardUnit",
+    show: false,
+  },
   {
     text: i18n.t("general.date-added"),
     value: "createdAt",
@@ -231,7 +242,12 @@ const { store: unitStore, actions: unitActions } = useUnitStore();
 
 // ============================================================
 // Form items (shared)
-const formItems: AutoFormItems = [
+type StandardizedUnitTypeOption = {
+  text: string;
+  value: StandardizedUnitType;
+};
+
+const formItems = computed<AutoFormItems>(() => [
   {
     cols: 8,
     label: i18n.t("general.name"),
@@ -262,6 +278,59 @@ const formItems: AutoFormItems = [
     varName: "description",
     type: fieldTypes.TEXT,
   },
+  {
+    section: i18n.t("data-pages.units.standardization"),
+    sectionDetails: i18n.t("data-pages.units.standardization-description"),
+    cols: 2,
+    varName: "standardQuantity",
+    type: fieldTypes.NUMBER,
+    numberInputConfig: {
+      min: 0,
+      max: undefined,
+      precision: undefined,
+      controlVariant: "hidden",
+    },
+  },
+  {
+    cols: 10,
+    varName: "standardUnit",
+    type: fieldTypes.SELECT,
+    selectReturnValue: "value",
+    options: [
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.fluid-ounce"),
+        value: "fluid_ounce",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.cup"),
+        value: "cup",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.ounce"),
+        value: "ounce",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.pound"),
+        value: "pound",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.milliliter"),
+        value: "milliliter",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.liter"),
+        value: "liter",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.gram"),
+        value: "gram",
+      },
+      {
+        text: i18n.t("data-pages.units.standard-unit-labels.kilogram"),
+        value: "kilogram",
+      },
+    ] as StandardizedUnitTypeOption[],
+  },
   {
     section: i18n.t("general.settings"),
     cols: 4,
@@ -275,7 +344,7 @@ const formItems: AutoFormItems = [
     varName: "fraction",
     type: fieldTypes.BOOLEAN,
   },
-];
+]);
 
 // ============================================================
 // Create
diff --git a/frontend/types/auto-forms.ts b/frontend/types/auto-forms.ts
index f52165688..b232f66b6 100644
--- a/frontend/types/auto-forms.ts
+++ b/frontend/types/auto-forms.ts
@@ -1,6 +1,15 @@
 import type { VForm as VuetifyForm } from "vuetify/components/VForm";
 
-type FormFieldType = "text" | "textarea" | "list" | "select" | "object" | "boolean" | "color" | "password";
+type FormFieldType
+  = | "text"
+    | "textarea"
+    | "number"
+    | "list"
+    | "select"
+    | "object"
+    | "boolean"
+    | "color"
+    | "password";
 
 export type FormValidationRule = (value: any) => boolean | string;
 
@@ -9,6 +18,13 @@ export interface FormSelectOption {
   value?: string;
 }
 
+export interface FormFieldNumberInputConfig {
+  min?: number;
+  max?: number;
+  precision?: number;
+  controlVariant?: "split" | "default" | "hidden" | "stacked";
+}
+
 export interface FormField {
   section?: string;
   sectionDetails?: string;
@@ -20,6 +36,7 @@ export interface FormField {
   rules?: FormValidationRule[];
   disableUpdate?: boolean;
   disableCreate?: boolean;
+  numberInputConfig?: FormFieldNumberInputConfig;
   options?: FormSelectOption[];
   selectReturnValue?: "text" | "value";
 }
diff --git a/mealie/alembic/versions/2026-02-21-17.59.01_a39c7f1826e3_add_unit_standardization_fields.py b/mealie/alembic/versions/2026-02-21-17.59.01_a39c7f1826e3_add_unit_standardization_fields.py
new file mode 100644
index 000000000..c0898392a
--- /dev/null
+++ b/mealie/alembic/versions/2026-02-21-17.59.01_a39c7f1826e3_add_unit_standardization_fields.py
@@ -0,0 +1,106 @@
+"""add unit standardization fields
+
+Revision ID: a39c7f1826e3
+Revises: 1d9a002d7234
+Create Date: 2026-02-21 17:59:01.161812
+
+"""
+
+import sqlalchemy as sa
+from sqlalchemy import orm
+from alembic import op
+from mealie.repos.repository_units import RepositoryUnit
+from mealie.core.root_logger import get_logger
+from mealie.db.models._model_utils.guid import GUID
+from mealie.repos.seed.seeders import IngredientUnitsSeeder
+from mealie.lang.locale_config import LOCALE_CONFIG
+
+# revision identifiers, used by Alembic.
+revision = "a39c7f1826e3"
+down_revision: str | None = "1d9a002d7234"
+branch_labels: str | tuple[str, ...] | None = None
+depends_on: str | tuple[str, ...] | None = None
+
+logger = get_logger()
+
+
+class SqlAlchemyBase(orm.DeclarativeBase): ...
+
+
+class IngredientUnitModel(SqlAlchemyBase):
+    __tablename__ = "ingredient_units"
+
+    id: orm.Mapped[GUID] = orm.mapped_column(GUID, primary_key=True, default=GUID.generate)
+    name: orm.Mapped[str | None] = orm.mapped_column(sa.String)
+    plural_name: orm.Mapped[str | None] = orm.mapped_column(sa.String)
+    abbreviation: orm.Mapped[str | None] = orm.mapped_column(sa.String)
+    plural_abbreviation: orm.Mapped[str | None] = orm.mapped_column(sa.String)
+    standard_quantity: orm.Mapped[float | None] = orm.mapped_column(sa.Float)
+    standard_unit: orm.Mapped[str | None] = orm.mapped_column(sa.String)
+
+
+def populate_standards() -> None:
+    bind = op.get_bind()
+
+    session = orm.Session(bind)
+
+    # We aren't using most of the functionality of this class, so we pass dummy args
+    repo = RepositoryUnit(None, None, None, None, group_id=None)  # type: ignore
+
+    stmt = sa.select(IngredientUnitModel)
+    units = session.execute(stmt).scalars().all()
+    if not units:
+        return
+
+    # Manually build repo._standardized_unit_map with all locales
+    repo._standardized_unit_map = {}
+    for locale in LOCALE_CONFIG:
+        locale_file = IngredientUnitsSeeder.get_file(locale)
+        for unit_key, unit in IngredientUnitsSeeder.load_file(locale_file).items():
+            for prop in ["name", "plural_name", "abbreviation"]:
+                val = unit.get(prop)
+                if val and isinstance(val, str):
+                    repo._standardized_unit_map[val.strip().lower()] = unit_key
+
+    for unit in units:
+        unit_data = {
+            "name": unit.name,
+            "plural_name": unit.plural_name,
+            "abbreviation": unit.abbreviation,
+            "plural_abbreviation": unit.plural_abbreviation,
+        }
+
+        standardized_data = repo._add_standardized_unit(unit_data)
+        std_q = standardized_data.get("standard_quantity")
+        std_u = standardized_data.get("standard_unit")
+        if std_q and std_u:
+            logger.info(f"Found unit '{unit.name}', which is standardized as '{std_q} * {std_u}'")
+            unit.standard_quantity = std_q
+            unit.standard_unit = std_u
+
+    session.commit()
+    session.close()
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("ingredient_units", schema=None) as batch_op:
+        batch_op.add_column(sa.Column("standard_quantity", sa.Float(), nullable=True))
+        batch_op.add_column(sa.Column("standard_unit", sa.String(), nullable=True))
+
+    # ### end Alembic commands ###
+
+    # Populate standardized units for existing records
+    try:
+        populate_standards()
+    except Exception:
+        logger.exception("Failed to populate unit standards, skipping...")
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("ingredient_units", schema=None) as batch_op:
+        batch_op.drop_column("standard_unit")
+        batch_op.drop_column("standard_quantity")
+
+    # ### end Alembic commands ###
diff --git a/mealie/db/models/recipe/ingredient.py b/mealie/db/models/recipe/ingredient.py
index f65830953..82e6f89af 100644
--- a/mealie/db/models/recipe/ingredient.py
+++ b/mealie/db/models/recipe/ingredient.py
@@ -52,6 +52,10 @@ class IngredientUnitModel(SqlAlchemyBase, BaseMixins):
         cascade="all, delete, delete-orphan",
     )
 
+    # Standardization
+    standard_quantity: Mapped[float | None] = mapped_column(Float)
+    standard_unit: Mapped[str | None] = mapped_column(String)
+
     # Automatically updated by sqlalchemy event, do not write to this manually
     name_normalized: Mapped[str | None] = mapped_column(sa.String, index=True)
     plural_name_normalized: Mapped[str | None] = mapped_column(sa.String, index=True)
diff --git a/mealie/lang/locale_config.py b/mealie/lang/locale_config.py
index 9ebef497f..1c7d9dbca 100644
--- a/mealie/lang/locale_config.py
+++ b/mealie/lang/locale_config.py
@@ -15,52 +15,63 @@ class LocalePluralFoodHandling(StrEnum):
 
 @dataclass
 class LocaleConfig:
+    key: str
     name: str
     dir: LocaleTextDirection = LocaleTextDirection.LTR
     plural_food_handling: LocalePluralFoodHandling = LocalePluralFoodHandling.ALWAYS
 
 
 LOCALE_CONFIG: dict[str, LocaleConfig] = {
-    "af-ZA": LocaleConfig(name="Afrikaans (Afrikaans)"),
-    "ar-SA": LocaleConfig(name="العربية (Arabic)", dir=LocaleTextDirection.RTL),
-    "bg-BG": LocaleConfig(name="Български (Bulgarian)"),
-    "ca-ES": LocaleConfig(name="Català (Catalan)"),
-    "cs-CZ": LocaleConfig(name="Čeština (Czech)"),
-    "da-DK": LocaleConfig(name="Dansk (Danish)"),
-    "de-DE": LocaleConfig(name="Deutsch (German)"),
-    "el-GR": LocaleConfig(name="Ελληνικά (Greek)"),
-    "en-GB": LocaleConfig(name="British English", plural_food_handling=LocalePluralFoodHandling.WITHOUT_UNIT),
-    "en-US": LocaleConfig(name="American English", plural_food_handling=LocalePluralFoodHandling.WITHOUT_UNIT),
-    "es-ES": LocaleConfig(name="Español (Spanish)"),
-    "et-EE": LocaleConfig(name="Eesti (Estonian)"),
-    "fi-FI": LocaleConfig(name="Suomi (Finnish)"),
-    "fr-BE": LocaleConfig(name="Belge (Belgian)"),
-    "fr-CA": LocaleConfig(name="Français canadien (Canadian French)"),
-    "fr-FR": LocaleConfig(name="Français (French)"),
-    "gl-ES": LocaleConfig(name="Galego (Galician)"),
-    "he-IL": LocaleConfig(name="עברית (Hebrew)", dir=LocaleTextDirection.RTL),
-    "hr-HR": LocaleConfig(name="Hrvatski (Croatian)"),
-    "hu-HU": LocaleConfig(name="Magyar (Hungarian)"),
-    "is-IS": LocaleConfig(name="Íslenska (Icelandic)"),
-    "it-IT": LocaleConfig(name="Italiano (Italian)"),
-    "ja-JP": LocaleConfig(name="日本語 (Japanese)", plural_food_handling=LocalePluralFoodHandling.NEVER),
-    "ko-KR": LocaleConfig(name="한국어 (Korean)", plural_food_handling=LocalePluralFoodHandling.NEVER),
-    "lt-LT": LocaleConfig(name="Lietuvių (Lithuanian)"),
-    "lv-LV": LocaleConfig(name="Latviešu (Latvian)"),
-    "nl-NL": LocaleConfig(name="Nederlands (Dutch)"),
-    "no-NO": LocaleConfig(name="Norsk (Norwegian)"),
-    "pl-PL": LocaleConfig(name="Polski (Polish)"),
-    "pt-BR": LocaleConfig(name="Português do Brasil (Brazilian Portuguese)"),
-    "pt-PT": LocaleConfig(name="Português (Portuguese)"),
-    "ro-RO": LocaleConfig(name="Română (Romanian)"),
-    "ru-RU": LocaleConfig(name="Pусский (Russian)"),
-    "sk-SK": LocaleConfig(name="Slovenčina (Slovak)"),
-    "sl-SI": LocaleConfig(name="Slovenščina (Slovenian)"),
-    "sr-SP": LocaleConfig(name="српски (Serbian)"),
-    "sv-SE": LocaleConfig(name="Svenska (Swedish)"),
-    "tr-TR": LocaleConfig(name="Türkçe (Turkish)", plural_food_handling=LocalePluralFoodHandling.NEVER),
-    "uk-UA": LocaleConfig(name="Українська (Ukrainian)"),
-    "vi-VN": LocaleConfig(name="Tiếng Việt (Vietnamese)", plural_food_handling=LocalePluralFoodHandling.NEVER),
-    "zh-CN": LocaleConfig(name="简体中文 (Chinese simplified)", plural_food_handling=LocalePluralFoodHandling.NEVER),
-    "zh-TW": LocaleConfig(name="繁體中文 (Chinese traditional)", plural_food_handling=LocalePluralFoodHandling.NEVER),
+    "af-ZA": LocaleConfig(key="af-ZA", name="Afrikaans (Afrikaans)"),
+    "ar-SA": LocaleConfig(key="ar-SA", name="العربية (Arabic)", dir=LocaleTextDirection.RTL),
+    "bg-BG": LocaleConfig(key="bg-BG", name="Български (Bulgarian)"),
+    "ca-ES": LocaleConfig(key="ca-ES", name="Català (Catalan)"),
+    "cs-CZ": LocaleConfig(key="cs-CZ", name="Čeština (Czech)"),
+    "da-DK": LocaleConfig(key="da-DK", name="Dansk (Danish)"),
+    "de-DE": LocaleConfig(key="de-DE", name="Deutsch (German)"),
+    "el-GR": LocaleConfig(key="el-GR", name="Ελληνικά (Greek)"),
+    "en-GB": LocaleConfig(
+        key="en-GB", name="British English", plural_food_handling=LocalePluralFoodHandling.WITHOUT_UNIT
+    ),
+    "en-US": LocaleConfig(
+        key="en-US", name="American English", plural_food_handling=LocalePluralFoodHandling.WITHOUT_UNIT
+    ),
+    "es-ES": LocaleConfig(key="es-ES", name="Español (Spanish)"),
+    "et-EE": LocaleConfig(key="et-EE", name="Eesti (Estonian)"),
+    "fi-FI": LocaleConfig(key="fi-FI", name="Suomi (Finnish)"),
+    "fr-BE": LocaleConfig(key="fr-BE", name="Belge (Belgian)"),
+    "fr-CA": LocaleConfig(key="fr-CA", name="Français canadien (Canadian French)"),
+    "fr-FR": LocaleConfig(key="fr-FR", name="Français (French)"),
+    "gl-ES": LocaleConfig(key="gl-ES", name="Galego (Galician)"),
+    "he-IL": LocaleConfig(key="he-IL", name="עברית (Hebrew)", dir=LocaleTextDirection.RTL),
+    "hr-HR": LocaleConfig(key="hr-HR", name="Hrvatski (Croatian)"),
+    "hu-HU": LocaleConfig(key="hu-HU", name="Magyar (Hungarian)"),
+    "is-IS": LocaleConfig(key="is-IS", name="Íslenska (Icelandic)"),
+    "it-IT": LocaleConfig(key="it-IT", name="Italiano (Italian)"),
+    "ja-JP": LocaleConfig(key="ja-JP", name="日本語 (Japanese)", plural_food_handling=LocalePluralFoodHandling.NEVER),
+    "ko-KR": LocaleConfig(key="ko-KR", name="한국어 (Korean)", plural_food_handling=LocalePluralFoodHandling.NEVER),
+    "lt-LT": LocaleConfig(key="lt-LT", name="Lietuvių (Lithuanian)"),
+    "lv-LV": LocaleConfig(key="lv-LV", name="Latviešu (Latvian)"),
+    "nl-NL": LocaleConfig(key="nl-NL", name="Nederlands (Dutch)"),
+    "no-NO": LocaleConfig(key="no-NO", name="Norsk (Norwegian)"),
+    "pl-PL": LocaleConfig(key="pl-PL", name="Polski (Polish)"),
+    "pt-BR": LocaleConfig(key="pt-BR", name="Português do Brasil (Brazilian Portuguese)"),
+    "pt-PT": LocaleConfig(key="pt-PT", name="Português (Portuguese)"),
+    "ro-RO": LocaleConfig(key="ro-RO", name="Română (Romanian)"),
+    "ru-RU": LocaleConfig(key="ru-RU", name="Pусский (Russian)"),
+    "sk-SK": LocaleConfig(key="sk-SK", name="Slovenčina (Slovak)"),
+    "sl-SI": LocaleConfig(key="sl-SI", name="Slovenščina (Slovenian)"),
+    "sr-SP": LocaleConfig(key="sr-SP", name="српски (Serbian)"),
+    "sv-SE": LocaleConfig(key="sv-SE", name="Svenska (Swedish)"),
+    "tr-TR": LocaleConfig(key="tr-TR", name="Türkçe (Turkish)", plural_food_handling=LocalePluralFoodHandling.NEVER),
+    "uk-UA": LocaleConfig(key="uk-UA", name="Українська (Ukrainian)"),
+    "vi-VN": LocaleConfig(
+        key="vi-VN", name="Tiếng Việt (Vietnamese)", plural_food_handling=LocalePluralFoodHandling.NEVER
+    ),
+    "zh-CN": LocaleConfig(
+        key="zh-CN", name="简体中文 (Chinese simplified)", plural_food_handling=LocalePluralFoodHandling.NEVER
+    ),
+    "zh-TW": LocaleConfig(
+        key="zh-TW", name="繁體中文 (Chinese traditional)", plural_food_handling=LocalePluralFoodHandling.NEVER
+    ),
 }
diff --git a/mealie/repos/repository_units.py b/mealie/repos/repository_units.py
index b9e3a1496..3de3b571b 100644
--- a/mealie/repos/repository_units.py
+++ b/mealie/repos/repository_units.py
@@ -1,17 +1,119 @@
-from pydantic import UUID4
+from collections.abc import Iterable
+
+from pydantic import UUID4, BaseModel
 from sqlalchemy import select
 
 from mealie.db.models.recipe.ingredient import IngredientUnitModel
-from mealie.schema.recipe.recipe_ingredient import IngredientUnit
+from mealie.lang.providers import get_locale_context
+from mealie.schema.recipe.recipe_ingredient import IngredientUnit, StandardizedUnitType
 
 from .repository_generic import GroupRepositoryGeneric
 
 
 class RepositoryUnit(GroupRepositoryGeneric[IngredientUnit, IngredientUnitModel]):
+    _standardized_unit_map: dict[str, str] | None = None
+
+    @property
+    def standardized_unit_map(self) -> dict[str, str]:
+        """A map of potential known units to its standardized name in our seed data"""
+
+        if self._standardized_unit_map is None:
+            from .seed.seeders import IngredientUnitsSeeder
+
+            ctx = get_locale_context()
+            if ctx:
+                locale = ctx[1].key
+            else:
+                locale = None
+
+            self._standardized_unit_map = {}
+            locale_file = IngredientUnitsSeeder.get_file(locale=locale)
+            for unit_key, unit in IngredientUnitsSeeder.load_file(locale_file).items():
+                for prop in ["name", "plural_name", "abbreviation"]:
+                    val = unit.get(prop)
+                    if val and isinstance(val, str):
+                        self._standardized_unit_map[val.strip().lower()] = unit_key
+
+        return self._standardized_unit_map
+
     def _get_unit(self, id: UUID4) -> IngredientUnitModel:
         stmt = select(self.model).filter_by(**self._filter_builder(**{"id": id}))
         return self.session.execute(stmt).scalars().one()
 
+    def _add_standardized_unit(self, data: BaseModel | dict) -> dict:
+        if not isinstance(data, dict):
+            data = data.model_dump()
+
+        # Don't overwrite user data if it exists
+        if data.get("standard_quantity") is not None or data.get("standard_unit") is not None:
+            return data
+
+        # Compare name attrs to translation files and see if there's a match to a known standard unit
+        for prop in ["name", "plural_name", "abbreviation", "plural_abbreviation"]:
+            val = data.get(prop)
+            if not (val and isinstance(val, str)):
+                continue
+
+            standardized_unit_key = self.standardized_unit_map.get(val.strip().lower())
+            if not standardized_unit_key:
+                continue
+
+            match standardized_unit_key:
+                case "teaspoon":
+                    data["standard_quantity"] = 1 / 6
+                    data["standard_unit"] = StandardizedUnitType.FLUID_OUNCE
+                case "tablespoon":
+                    data["standard_quantity"] = 1 / 2
+                    data["standard_unit"] = StandardizedUnitType.FLUID_OUNCE
+                case "cup":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.CUP
+                case "fluid-ounce":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.FLUID_OUNCE
+                case "pint":
+                    data["standard_quantity"] = 2
+                    data["standard_unit"] = StandardizedUnitType.CUP
+                case "quart":
+                    data["standard_quantity"] = 4
+                    data["standard_unit"] = StandardizedUnitType.CUP
+                case "gallon":
+                    data["standard_quantity"] = 16
+                    data["standard_unit"] = StandardizedUnitType.CUP
+                case "milliliter":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.MILLILITER
+                case "liter":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.LITER
+                case "pound":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.POUND
+                case "ounce":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.OUNCE
+                case "gram":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.GRAM
+                case "kilogram":
+                    data["standard_quantity"] = 1
+                    data["standard_unit"] = StandardizedUnitType.KILOGRAM
+                case "milligram":
+                    data["standard_quantity"] = 1 / 1000
+                    data["standard_unit"] = StandardizedUnitType.GRAM
+                case _:
+                    continue
+
+        return data
+
+    def create(self, data: IngredientUnit | dict) -> IngredientUnit:
+        data = self._add_standardized_unit(data)
+        return super().create(data)
+
+    def create_many(self, data: Iterable[IngredientUnit | dict]) -> list[IngredientUnit]:
+        data = [self._add_standardized_unit(i) for i in data]
+        return super().create_many(data)
+
     def merge(self, from_unit: UUID4, to_unit: UUID4) -> IngredientUnit | None:
         from_model = self._get_unit(from_unit)
         to_model = self._get_unit(to_unit)
diff --git a/mealie/repos/seed/_abstract_seeder.py b/mealie/repos/seed/_abstract_seeder.py
index 7f9ce3d4e..b77fd718c 100644
--- a/mealie/repos/seed/_abstract_seeder.py
+++ b/mealie/repos/seed/_abstract_seeder.py
@@ -1,3 +1,4 @@
+import json
 from abc import ABC, abstractmethod
 from logging import Logger
 from pathlib import Path
@@ -11,6 +12,8 @@ class AbstractSeeder(ABC):
     Abstract class for seeding data.
     """
 
+    resources = Path(__file__).parent / "resources"
+
     def __init__(self, db: AllRepositories, logger: Logger | None = None):
         """
         Initialize the abstract seeder.
@@ -19,7 +22,14 @@ class AbstractSeeder(ABC):
         """
         self.repos = db
         self.logger = logger or get_logger("Data Seeder")
-        self.resources = Path(__file__).parent / "resources"
+
+    @classmethod
+    @abstractmethod
+    def get_file(self, locale: str | None = None) -> Path: ...
+
+    @classmethod
+    def load_file(self, file: Path) -> dict[str, dict]:
+        return json.loads(file.read_text(encoding="utf-8"))
 
     @abstractmethod
     def seed(self, locale: str | None = None) -> None: ...
diff --git a/mealie/repos/seed/seeders.py b/mealie/repos/seed/seeders.py
index 72f68c453..f0c1dfd27 100644
--- a/mealie/repos/seed/seeders.py
+++ b/mealie/repos/seed/seeders.py
@@ -1,4 +1,3 @@
-import json
 import pathlib
 from collections.abc import Generator
 from functools import cached_property
@@ -21,9 +20,10 @@ class MultiPurposeLabelSeeder(AbstractSeeder):
     def service(self):
         return MultiPurposeLabelService(self.repos)
 
-    def get_file(self, locale: str | None = None) -> pathlib.Path:
+    @classmethod
+    def get_file(cls, locale: str | None = None) -> pathlib.Path:
         # Get the labels from the foods seed file now
-        locale_path = self.resources / "foods" / "locales" / f"{locale}.json"
+        locale_path = cls.resources / "foods" / "locales" / f"{locale}.json"
         return locale_path if locale_path.exists() else foods.en_US
 
     def get_all_labels(self) -> list[MultiPurposeLabelOut]:
@@ -34,7 +34,7 @@ class MultiPurposeLabelSeeder(AbstractSeeder):
 
         current_label_names = {label.name for label in self.get_all_labels()}
         # load from the foods locale file and remove any empty strings
-        seed_label_names = set(filter(None, json.loads(file.read_text(encoding="utf-8")).keys()))  # type: set[str]
+        seed_label_names = set(filter(None, self.load_file(file).keys()))  # type: set[str]
         # only seed new labels
         to_seed_labels = seed_label_names - current_label_names
         for label in to_seed_labels:
@@ -53,8 +53,9 @@ class MultiPurposeLabelSeeder(AbstractSeeder):
 
 
 class IngredientUnitsSeeder(AbstractSeeder):
-    def get_file(self, locale: str | None = None) -> pathlib.Path:
-        locale_path = self.resources / "units" / "locales" / f"{locale}.json"
+    @classmethod
+    def get_file(cls, locale: str | None = None) -> pathlib.Path:
+        locale_path = cls.resources / "units" / "locales" / f"{locale}.json"
         return locale_path if locale_path.exists() else units.en_US
 
     def get_all_units(self) -> list[IngredientUnit]:
@@ -64,7 +65,7 @@ class IngredientUnitsSeeder(AbstractSeeder):
         file = self.get_file(locale)
 
         seen_unit_names = {unit.name for unit in self.get_all_units()}
-        for unit in json.loads(file.read_text(encoding="utf-8")).values():
+        for unit in self.load_file(file).values():
             if unit["name"] in seen_unit_names:
                 continue
 
@@ -88,8 +89,9 @@ class IngredientUnitsSeeder(AbstractSeeder):
 
 
 class IngredientFoodsSeeder(AbstractSeeder):
-    def get_file(self, locale: str | None = None) -> pathlib.Path:
-        locale_path = self.resources / "foods" / "locales" / f"{locale}.json"
+    @classmethod
+    def get_file(cls, locale: str | None = None) -> pathlib.Path:
+        locale_path = cls.resources / "foods" / "locales" / f"{locale}.json"
         return locale_path if locale_path.exists() else foods.en_US
 
     def get_label(self, value: str) -> MultiPurposeLabelOut | None:
@@ -103,7 +105,7 @@ class IngredientFoodsSeeder(AbstractSeeder):
 
         # get all current unique foods
         seen_foods_names = {food.name for food in self.get_all_foods()}
-        for label, values in json.loads(file.read_text(encoding="utf-8")).items():
+        for label, values in self.load_file(file).items():
             label_out = self.get_label(label)
 
             for food_name, attributes in values["foods"].items():
diff --git a/mealie/schema/recipe/__init__.py b/mealie/schema/recipe/__init__.py
index 0d91b89a4..48785e4a4 100644
--- a/mealie/schema/recipe/__init__.py
+++ b/mealie/schema/recipe/__init__.py
@@ -67,6 +67,7 @@ from .recipe_ingredient import (
     RegisteredParser,
     SaveIngredientFood,
     SaveIngredientUnit,
+    StandardizedUnitType,
     UnitFoodBase,
 )
 from .recipe_notes import RecipeNote
@@ -159,6 +160,7 @@ __all__ = [
     "RegisteredParser",
     "SaveIngredientFood",
     "SaveIngredientUnit",
+    "StandardizedUnitType",
     "UnitFoodBase",
     "RecipeSuggestionQuery",
     "RecipeSuggestionResponse",
diff --git a/mealie/schema/recipe/recipe_ingredient.py b/mealie/schema/recipe/recipe_ingredient.py
index 4a32f0ff9..3ccb06a5f 100644
--- a/mealie/schema/recipe/recipe_ingredient.py
+++ b/mealie/schema/recipe/recipe_ingredient.py
@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import datetime
 import enum
+from enum import StrEnum
 from fractions import Fraction
 from typing import ClassVar
 from uuid import UUID, uuid4
@@ -34,6 +35,28 @@ def display_fraction(fraction: Fraction):
     )
 
 
+class StandardizedUnitType(StrEnum):
+    """
+    An arbitrary list of standardized units supported by unit conversions.
+    The backend doesn't really care what standardized unit you use, as long as it's recognized,
+    but defining them here keeps it consistant with the frontend.
+    """
+
+    # Imperial
+    FLUID_OUNCE = "fluid_ounce"
+    CUP = "cup"
+
+    OUNCE = "ounce"
+    POUND = "pound"
+
+    # Metric
+    MILLILITER = "milliliter"
+    LITER = "liter"
+
+    GRAM = "gram"
+    KILOGRAM = "kilogram"
+
+
 class UnitFoodBase(MealieModel):
     id: UUID4 | None = None
     name: str
@@ -109,9 +132,6 @@ class IngredientFood(CreateIngredientFood):
         except AttributeError:
             return v
 
-    def is_on_hand(self, household_slug: str) -> bool:
-        return household_slug in self.households_with_tool
-
 
 class IngredientFoodPagination(PaginationBase):
     items: list[IngredientFood]
@@ -130,7 +150,21 @@ class CreateIngredientUnit(UnitFoodBase):
     abbreviation: str = ""
     plural_abbreviation: str | None = ""
     use_abbreviation: bool = False
+
     aliases: list[CreateIngredientUnitAlias] = []
+    standard_quantity: float | None = None
+    standard_unit: str | None = None
+
+    @model_validator(mode="after")
+    def validate_standardization_fields(self):
+        # If one is set, the other must be set.
+        # If quantity is <= 0, it's considered not set.
+        if not self.standard_unit:
+            self.standard_quantity = self.standard_unit = None
+        elif not ((self.standard_quantity or 0) > 0):
+            self.standard_quantity = self.standard_unit = None
+
+        return self
 
 
 class SaveIngredientUnit(CreateIngredientUnit):
diff --git a/mealie/schema/recipe/recipe_tool.py b/mealie/schema/recipe/recipe_tool.py
index 9cc8ff4f1..9c541cd05 100644
--- a/mealie/schema/recipe/recipe_tool.py
+++ b/mealie/schema/recipe/recipe_tool.py
@@ -32,9 +32,6 @@ class RecipeToolOut(RecipeToolCreate):
         except AttributeError:
             return v
 
-    def is_on_hand(self, household_slug: str) -> bool:
-        return household_slug in self.households_with_tool
-
     @classmethod
     def loader_options(cls) -> list[LoaderOption]:
         return [
diff --git a/mealie/services/household_services/shopping_lists.py b/mealie/services/household_services/shopping_lists.py
index 4cdb6abf1..831877ca2 100644
--- a/mealie/services/household_services/shopping_lists.py
+++ b/mealie/services/household_services/shopping_lists.py
@@ -28,6 +28,7 @@ from mealie.schema.recipe.recipe_ingredient import (
 )
 from mealie.schema.response.pagination import OrderDirection, PaginationQuery
 from mealie.services.parser_services._base import DataMatcher
+from mealie.services.parser_services.parser_utils import UnitConverter, merge_quantity_and_unit
 
 
 class ShoppingListService:
@@ -41,8 +42,7 @@ class ShoppingListService:
         self.list_refs = repos.group_shopping_list_recipe_refs
         self.data_matcher = DataMatcher(self.repos, food_fuzzy_match_threshold=self.DEFAULT_FOOD_FUZZY_MATCH_THRESHOLD)
 
-    @staticmethod
-    def can_merge(item1: ShoppingListItemBase, item2: ShoppingListItemBase) -> bool:
+    def can_merge(self, item1: ShoppingListItemBase, item2: ShoppingListItemBase) -> bool:
         """Check to see if this item can be merged with another item"""
 
         if any(
@@ -50,16 +50,28 @@ class ShoppingListService:
                 item1.checked,
                 item2.checked,
                 item1.food_id != item2.food_id,
-                item1.unit_id != item2.unit_id,
             ]
         ):
             return False
 
+        # check if units match or if they're compatable
+        if item1.unit_id != item2.unit_id:
+            item1_unit = item1.unit or self.data_matcher.units_by_id.get(item1.unit_id)
+            item2_unit = item2.unit or self.data_matcher.units_by_id.get(item2.unit_id)
+            if not (item1_unit and item1_unit.standard_unit):
+                return False
+            if not (item2_unit and item2_unit.standard_unit):
+                return False
+
+            uc = UnitConverter()
+            if not uc.can_convert(item1_unit.standard_unit, item2_unit.standard_unit):
+                return False
+
         # if foods match, we can merge, otherwise compare the notes
         return bool(item1.food_id) or item1.note == item2.note
 
-    @staticmethod
     def merge_items(
+        self,
         from_item: ShoppingListItemCreate | ShoppingListItemUpdateBulk,
         to_item: ShoppingListItemCreate | ShoppingListItemUpdateBulk | ShoppingListItemOut,
     ) -> ShoppingListItemUpdate:
@@ -69,7 +81,20 @@ class ShoppingListService:
         Attributes of the `to_item` take priority over the `from_item`, except extras with overlapping keys
         """
 
-        to_item.quantity += from_item.quantity
+        to_item_unit = to_item.unit or self.data_matcher.units_by_id.get(to_item.unit_id)
+        from_item_unit = from_item.unit or self.data_matcher.units_by_id.get(from_item.unit_id)
+        if to_item_unit and to_item_unit.standard_unit and from_item_unit and from_item_unit.standard_unit:
+            merged_qty, merged_unit = merge_quantity_and_unit(
+                from_item.quantity or 0, from_item_unit, to_item.quantity or 0, to_item_unit
+            )
+            to_item.quantity = merged_qty
+            to_item.unit_id = merged_unit.id
+            to_item.unit = merged_unit
+
+        else:
+            # No conversion needed, just sum the quantities
+            to_item.quantity += from_item.quantity
+
         if to_item.note != from_item.note:
             to_item.note = " | ".join([note for note in [to_item.note, from_item.note] if note])
 
diff --git a/mealie/services/parser_services/_base.py b/mealie/services/parser_services/_base.py
index 89fc8f290..b3662990d 100644
--- a/mealie/services/parser_services/_base.py
+++ b/mealie/services/parser_services/_base.py
@@ -29,18 +29,38 @@ class DataMatcher:
 
         self._food_fuzzy_match_threshold = food_fuzzy_match_threshold
         self._unit_fuzzy_match_threshold = unit_fuzzy_match_threshold
+
+        self._foods_by_id: dict[UUID4, IngredientFood] | None = None
+        self._units_by_id: dict[UUID4, IngredientUnit] | None = None
+
         self._foods_by_alias: dict[str, IngredientFood] | None = None
         self._units_by_alias: dict[str, IngredientUnit] | None = None
 
     @property
-    def foods_by_alias(self) -> dict[str, IngredientFood]:
-        if self._foods_by_alias is None:
+    def foods_by_id(self) -> dict[UUID4, IngredientFood]:
+        if self._foods_by_id is None:
             foods_repo = self.repos.ingredient_foods
             query = PaginationQuery(page=1, per_page=-1)
             all_foods = foods_repo.page_all(query).items
+            self._foods_by_id = {food.id: food for food in all_foods}
 
+        return self._foods_by_id
+
+    @property
+    def units_by_id(self) -> dict[UUID4, IngredientUnit]:
+        if self._units_by_id is None:
+            units_repo = self.repos.ingredient_units
+            query = PaginationQuery(page=1, per_page=-1)
+            all_units = units_repo.page_all(query).items
+            self._units_by_id = {unit.id: unit for unit in all_units}
+
+        return self._units_by_id
+
+    @property
+    def foods_by_alias(self) -> dict[str, IngredientFood]:
+        if self._foods_by_alias is None:
             foods_by_alias: dict[str, IngredientFood] = {}
-            for food in all_foods:
+            for food in self.foods_by_id.values():
                 if food.name:
                     foods_by_alias[IngredientFoodModel.normalize(food.name)] = food
                 if food.plural_name:
@@ -57,12 +77,8 @@ class DataMatcher:
     @property
     def units_by_alias(self) -> dict[str, IngredientUnit]:
         if self._units_by_alias is None:
-            units_repo = self.repos.ingredient_units
-            query = PaginationQuery(page=1, per_page=-1)
-            all_units = units_repo.page_all(query).items
-
             units_by_alias: dict[str, IngredientUnit] = {}
-            for unit in all_units:
+            for unit in self.units_by_id.values():
                 if unit.name:
                     units_by_alias[IngredientUnitModel.normalize(unit.name)] = unit
                 if unit.plural_name:
diff --git a/mealie/services/parser_services/parser_utils/__init__.py b/mealie/services/parser_services/parser_utils/__init__.py
index 481851a81..1593c92a3 100644
--- a/mealie/services/parser_services/parser_utils/__init__.py
+++ b/mealie/services/parser_services/parser_utils/__init__.py
@@ -1 +1,2 @@
 from .string_utils import *
+from .unit_utils import *
diff --git a/mealie/services/parser_services/parser_utils/unit_utils.py b/mealie/services/parser_services/parser_utils/unit_utils.py
new file mode 100644
index 000000000..ef73e7e29
--- /dev/null
+++ b/mealie/services/parser_services/parser_utils/unit_utils.py
@@ -0,0 +1,146 @@
+from typing import TYPE_CHECKING, Literal, overload
+
+from pint import Quantity, Unit, UnitRegistry
+
+if TYPE_CHECKING:
+    from mealie.schema.recipe.recipe_ingredient import CreateIngredientUnit
+
+
+class UnitNotFound(Exception):
+    """Raised when trying to access a unit not found in the unit registry."""
+
+    def __init__(self, message: str = "Unit not found in unit registry"):
+        self.message = message
+        super().__init__(self.message)
+
+    def __str__(self):
+        return f"{self.message}"
+
+
+class UnitConverter:
+    def __init__(self):
+        self.ureg = UnitRegistry()
+
+    def _resolve_ounce(self, unit_1: Unit, unit_2: Unit) -> tuple[Unit, Unit]:
+        """
+        Often times "ounce" is used in place of "fluid ounce" in recipes.
+        When trying to convert/combine ounces with a volume, we can assume it should have been a fluid ounce.
+        This function will convert ounces to fluid ounces if the other unit is a volume.
+        """
+
+        OUNCE = self.ureg("ounce")
+        FL_OUNCE = self.ureg("fluid_ounce")
+        VOLUME = "[length] ** 3"
+
+        if unit_1 == OUNCE and unit_2.dimensionality == VOLUME:
+            return FL_OUNCE, unit_2
+        if unit_2 == OUNCE and unit_1.dimensionality == VOLUME:
+            return unit_1, FL_OUNCE
+
+        return unit_1, unit_2
+
+    @overload
+    def parse(self, unit: str | Unit, strict: Literal[False] = False) -> str | Unit: ...
+
+    @overload
+    def parse(self, unit: str | Unit, strict: Literal[True]) -> Unit: ...
+
+    def parse(self, unit: str | Unit, strict: bool = False) -> str | Unit:
+        """
+        Parse a string unit into a pint.Unit.
+
+        If strict is False (default), returns a pint.Unit if it exists, otherwise returns the original string.
+        If strict is True, raises UnitNotFound instead of returning a string.
+        If the input is already a parsed pint.Unit, returns it as-is.
+        """
+        if isinstance(unit, Unit):
+            return unit
+
+        try:
+            return self.ureg(unit).units
+        except Exception as e:
+            if strict:
+                raise UnitNotFound(f"Unit '{unit}' not found in unit registry") from e
+            return unit
+
+    def can_convert(self, unit: str | Unit, to_unit: str | Unit) -> bool:
+        """Whether or not a given unit can be converted into another unit."""
+
+        unit = self.parse(unit)
+        to_unit = self.parse(to_unit)
+
+        if not (isinstance(unit, Unit) and isinstance(to_unit, Unit)):
+            return False
+
+        unit, to_unit = self._resolve_ounce(unit, to_unit)
+        return unit.is_compatible_with(to_unit)
+
+    def convert(self, quantity: float, unit: str | Unit, to_unit: str | Unit) -> tuple[float, Unit]:
+        """
+        Convert a quantity and a unit into another unit.
+
+        Returns tuple[quantity, unit]
+        """
+
+        unit = self.parse(unit, strict=True)
+        to_unit = self.parse(to_unit, strict=True)
+        unit, to_unit = self._resolve_ounce(unit, to_unit)
+
+        qty = quantity * unit
+        converted = qty.to(to_unit)
+        return float(converted.magnitude), converted.units
+
+    def merge(self, quantity_1: float, unit_1: str | Unit, quantity_2: float, unit_2: str | Unit) -> tuple[float, Unit]:
+        """Merge two quantities together"""
+
+        unit_1 = self.parse(unit_1, strict=True)
+        unit_2 = self.parse(unit_2, strict=True)
+        unit_1, unit_2 = self._resolve_ounce(unit_1, unit_2)
+
+        q1 = quantity_1 * unit_1
+        q2 = quantity_2 * unit_2
+
+        out: Quantity = q1 + q2
+        return float(out.magnitude), out.units
+
+
+def merge_quantity_and_unit[T: CreateIngredientUnit](
+    qty_1: float, unit_1: T, qty_2: float, unit_2: T
+) -> tuple[float, T]:
+    """
+    Merge a quantity and unit.
+
+    Returns tuple[quantity, unit]
+    """
+
+    if not (unit_1.standard_quantity and unit_1.standard_unit and unit_2.standard_quantity and unit_2.standard_unit):
+        raise ValueError("Both units must contain standardized unit data")
+
+    PINT_UNIT_1_TXT = "_mealie_unit_1"
+    PINT_UNIT_2_TXT = "_mealie_unit_2"
+
+    uc = UnitConverter()
+
+    # pre-process units to account for ounce -> fluid_ounce conversion
+    unit_1_standard = uc.parse(unit_1.standard_unit, strict=True)
+    unit_2_standard = uc.parse(unit_2.standard_unit, strict=True)
+    unit_1_standard, unit_2_standard = uc._resolve_ounce(unit_1_standard, unit_2_standard)
+
+    # create custon unit definition so pint can handle them natively
+    uc.ureg.define(f"{PINT_UNIT_1_TXT} = {unit_1.standard_quantity} * {unit_1_standard}")
+    uc.ureg.define(f"{PINT_UNIT_2_TXT} = {unit_2.standard_quantity} * {unit_2_standard}")
+
+    pint_unit_1 = uc.parse(PINT_UNIT_1_TXT)
+    pint_unit_2 = uc.parse(PINT_UNIT_2_TXT)
+
+    merged_q, merged_u = uc.merge(qty_1, pint_unit_1, qty_2, pint_unit_2)
+
+    # Convert to the bigger unit if quantity >= 1, else the smaller unit
+    merged_q, merged_u = uc.convert(merged_q, merged_u, max(pint_unit_1, pint_unit_2))
+    if abs(merged_q) < 1:
+        merged_q, merged_u = uc.convert(merged_q, merged_u, min(pint_unit_1, pint_unit_2))
+
+    if str(merged_u) == PINT_UNIT_1_TXT:
+        return merged_q, unit_1
+    else:
+        return merged_q, unit_2
diff --git a/pyproject.toml b/pyproject.toml
index c649bef61..caede87ef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,6 +46,7 @@ dependencies = [
     "typing-extensions==4.15.0",
     "itsdangerous==2.2.0",
     "ingredient-parser-nlp==2.5.0",
+    "pint>=0.25",
 ]
 
 [project.scripts]
diff --git a/tests/data/__init__.py b/tests/data/__init__.py
index 92c81ab68..dc23abb4a 100644
--- a/tests/data/__init__.py
+++ b/tests/data/__init__.py
@@ -4,6 +4,9 @@ CWD = Path(__file__).parent
 
 locale_dir = CWD / "locale"
 
+backup_version_1d9a002d7234_1 = CWD / "backups/backup-version-1d9a002d7234-1.zip"
+"""1d9a002d7234: add referenced_recipe to ingredients"""
+
 backup_version_44e8d670719d_1 = CWD / "backups/backup-version-44e8d670719d-1.zip"
 """44e8d670719d: add extras to shopping lists, list items, and ingredient foods"""
 
diff --git a/tests/data/backups/backup-version-1d9a002d7234-1.zip b/tests/data/backups/backup-version-1d9a002d7234-1.zip
new file mode 100644
index 000000000..b3d64a555
Binary files /dev/null and b/tests/data/backups/backup-version-1d9a002d7234-1.zip differ
diff --git a/tests/integration_tests/user_group_tests/test_group_seeder.py b/tests/integration_tests/user_group_tests/test_group_seeder.py
index 87c58475b..8788f154e 100644
--- a/tests/integration_tests/user_group_tests/test_group_seeder.py
+++ b/tests/integration_tests/user_group_tests/test_group_seeder.py
@@ -15,14 +15,12 @@ def test_seed_foods(api_client: TestClient, unique_user: TestUser):
     CREATED_FOODS = 2687
     database = unique_user.repos
 
-    # Check that the foods was created
     foods = database.ingredient_foods.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(foods) == 0
 
     resp = api_client.post(api_routes.groups_seeders_foods, json={"locale": "en-US"}, headers=unique_user.token)
     assert resp.status_code == 200
 
-    # Check that the foods was created
     foods = database.ingredient_foods.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(foods) == CREATED_FOODS
 
@@ -31,29 +29,37 @@ def test_seed_units(api_client: TestClient, unique_user: TestUser):
     CREATED_UNITS = 24
     database = unique_user.repos
 
-    # Check that the foods was created
     units = database.ingredient_units.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(units) == 0
 
     resp = api_client.post(api_routes.groups_seeders_units, json={"locale": "en-US"}, headers=unique_user.token)
     assert resp.status_code == 200
 
-    # Check that the foods was created
     units = database.ingredient_units.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(units) == CREATED_UNITS
 
+    # Check that the "pint" unit was created and includes standardized data
+    pint_found = False
+    for unit in units:
+        if unit.name != "pint":
+            continue
+
+        pint_found = True
+        assert unit.standard_quantity == 2
+        assert unit.standard_unit == "cup"
+
+    assert pint_found
+
 
 def test_seed_labels(api_client: TestClient, unique_user: TestUser):
     CREATED_LABELS = 32
     database = unique_user.repos
 
-    # Check that the foods was created
     labels = database.group_multi_purpose_labels.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(labels) == 0
 
     resp = api_client.post(api_routes.groups_seeders_labels, json={"locale": "en-US"}, headers=unique_user.token)
     assert resp.status_code == 200
 
-    # Check that the foods was created
     labels = database.group_multi_purpose_labels.page_all(PaginationQuery(page=1, per_page=-1)).items
     assert len(labels) == CREATED_LABELS
diff --git a/tests/integration_tests/user_household_tests/test_group_shopping_list_items.py b/tests/integration_tests/user_household_tests/test_group_shopping_list_items.py
index 83aaf8d85..641f37f28 100644
--- a/tests/integration_tests/user_household_tests/test_group_shopping_list_items.py
+++ b/tests/integration_tests/user_household_tests/test_group_shopping_list_items.py
@@ -7,7 +7,7 @@ from fastapi.testclient import TestClient
 from pydantic import UUID4
 
 from mealie.schema.household.group_shopping_list import ShoppingListItemOut, ShoppingListOut
-from mealie.schema.recipe.recipe_ingredient import SaveIngredientFood
+from mealie.schema.recipe.recipe_ingredient import IngredientUnit, SaveIngredientFood
 from tests import utils
 from tests.utils import api_routes
 from tests.utils.factories import random_int, random_string
@@ -641,6 +641,96 @@ def test_shopping_list_items_with_zero_quantity(
     assert len(as_json["listItems"]) == len(normal_items + zero_qty_items) - 1
 
 
+def test_shopping_list_merge_standard_unit(
+    api_client: TestClient, unique_user: TestUser, shopping_list: ShoppingListOut
+):
+    unit_1_cup_data = {"name": random_string(), "standardQuantity": 1, "standardUnit": "cup"}
+    unit_2_cup_data = {"name": random_string(), "standardQuantity": 2, "standardUnit": "cup"}
+    unit_1_out = api_client.post(api_routes.units, json=unit_1_cup_data, headers=unique_user.token)
+    unit_2_out = api_client.post(api_routes.units, json=unit_2_cup_data, headers=unique_user.token)
+
+    unit_1 = IngredientUnit.model_validate(unit_1_out.json())
+    unit_2 = IngredientUnit.model_validate(unit_2_out.json())
+
+    list_item_1_data = create_item(shopping_list.id, unit_id=str(unit_1.id), note="mealie-food")
+    list_item_2_data = create_item(shopping_list.id, unit_id=str(unit_2.id), note="mealie-food")
+    response = api_client.post(
+        api_routes.households_shopping_items_create_bulk,
+        json=[list_item_1_data, list_item_2_data],
+        headers=unique_user.token,
+    )
+
+    as_json = utils.assert_deserialize(response, 201)
+    assert len(as_json["createdItems"]) == 1
+
+    item_out = as_json["createdItems"][0]
+
+    # should use larger "2 cup" unit (a la "pint")
+    assert item_out["unitId"] == str(unit_2.id)
+    # calculate quantity by summing base "cup" amount and dividing by 2 (a la pints)
+    assert item_out["quantity"] == (list_item_1_data["quantity"] + (list_item_2_data["quantity"] * 2)) / 2
+
+
+def test_shopping_list_merge_standard_unit_different_foods(
+    api_client: TestClient, unique_user: TestUser, shopping_list: ShoppingListOut
+):
+    unit_1_cup_data = {"name": random_string(), "standardQuantity": 1, "standardUnit": "cup"}
+    unit_2_cup_data = {"name": random_string(), "standardQuantity": 2, "standardUnit": "cup"}
+    unit_1_out = api_client.post(api_routes.units, json=unit_1_cup_data, headers=unique_user.token)
+    unit_2_out = api_client.post(api_routes.units, json=unit_2_cup_data, headers=unique_user.token)
+
+    unit_1 = IngredientUnit.model_validate(unit_1_out.json())
+    unit_2 = IngredientUnit.model_validate(unit_2_out.json())
+
+    list_item_1_data = create_item(shopping_list.id, unit_id=str(unit_1.id), note="mealie-food-1")
+    list_item_2_data = create_item(shopping_list.id, unit_id=str(unit_2.id), note="mealie-food-2")
+    response = api_client.post(
+        api_routes.households_shopping_items_create_bulk,
+        json=[list_item_1_data, list_item_2_data],
+        headers=unique_user.token,
+    )
+
+    as_json = utils.assert_deserialize(response, 201)
+    assert len(as_json["createdItems"]) == 2
+    for in_data, out_data in zip(
+        [list_item_1_data, list_item_2_data], [as_json["createdItems"][0], as_json["createdItems"][1]], strict=True
+    ):
+        assert in_data["quantity"] == out_data["quantity"]
+        assert out_data["unit"]
+        assert in_data["unit_id"] == out_data["unit"]["id"]
+        assert in_data["note"] == out_data["note"]
+
+
+def test_shopping_list_merge_standard_unit_incompatible_units(
+    api_client: TestClient, unique_user: TestUser, shopping_list: ShoppingListOut
+):
+    unit_1_data = {"name": random_string(), "standardQuantity": 1, "standardUnit": "cup"}
+    unit_2_data = {"name": random_string(), "standardQuantity": 2, "standardUnit": "gram"}
+    unit_1_out = api_client.post(api_routes.units, json=unit_1_data, headers=unique_user.token)
+    unit_2_out = api_client.post(api_routes.units, json=unit_2_data, headers=unique_user.token)
+
+    unit_1 = IngredientUnit.model_validate(unit_1_out.json())
+    unit_2 = IngredientUnit.model_validate(unit_2_out.json())
+
+    list_item_1_data = create_item(shopping_list.id, unit_id=str(unit_1.id), note="mealie-food")
+    list_item_2_data = create_item(shopping_list.id, unit_id=str(unit_2.id), note="mealie-food")
+    response = api_client.post(
+        api_routes.households_shopping_items_create_bulk,
+        json=[list_item_1_data, list_item_2_data],
+        headers=unique_user.token,
+    )
+
+    as_json = utils.assert_deserialize(response, 201)
+    assert len(as_json["createdItems"]) == 2
+    for in_data, out_data in zip(
+        [list_item_1_data, list_item_2_data], [as_json["createdItems"][0], as_json["createdItems"][1]], strict=True
+    ):
+        assert in_data["quantity"] == out_data["quantity"]
+        assert out_data["unit"]
+        assert in_data["unit_id"] == out_data["unit"]["id"]
+        assert in_data["note"] == out_data["note"]
+
+
 def test_shopping_list_item_extras(
     api_client: TestClient, unique_user: TestUser, shopping_list: ShoppingListOut
 ) -> None:
diff --git a/tests/unit_tests/ingredient_parser/test_unit_utils.py b/tests/unit_tests/ingredient_parser/test_unit_utils.py
new file mode 100644
index 000000000..2c81f43c8
--- /dev/null
+++ b/tests/unit_tests/ingredient_parser/test_unit_utils.py
@@ -0,0 +1,309 @@
+import pint
+import pytest
+
+from mealie.schema.recipe.recipe_ingredient import CreateIngredientUnit
+from mealie.services.parser_services.parser_utils import UnitConverter, UnitNotFound, merge_quantity_and_unit
+from tests.utils import random_string
+
+
+def test_uc_parse_string():
+    uc = UnitConverter()
+    parsed = uc.parse("cup")
+
+    assert isinstance(parsed, pint.Unit)
+    assert (str(parsed)) == "cup"
+
+
+def test_uc_parse_unit():
+    uc = UnitConverter()
+    parsed = uc.parse(uc.parse("cup"))
+
+    assert isinstance(parsed, pint.Unit)
+    assert (str(parsed)) == "cup"
+
+
+def test_uc_parse_invalid():
+    uc = UnitConverter()
+    input_str = random_string()
+    parsed = uc.parse(input_str)
+
+    assert not isinstance(parsed, pint.Unit)
+    assert parsed == input_str
+
+
+def test_uc_parse_invalid_strict():
+    uc = UnitConverter()
+    input_str = random_string()
+
+    with pytest.raises(UnitNotFound):
+        uc.parse(input_str, strict=True)
+
+
+@pytest.mark.parametrize("pre_parse_1", [True, False])
+@pytest.mark.parametrize("pre_parse_2", [True, False])
+def test_can_convert(pre_parse_1: bool, pre_parse_2: bool):
+    unit_1 = "cup"
+    unit_2 = "pint"
+
+    uc = UnitConverter()
+    if pre_parse_1:
+        unit_1 = uc.parse(unit_1)
+    if pre_parse_2:
+        unit_2 = uc.parse(unit_2)
+
+    assert uc.can_convert(unit_1, unit_2)
+
+
+@pytest.mark.parametrize("pre_parse_1", [True, False])
+@pytest.mark.parametrize("pre_parse_2", [True, False])
+def test_cannot_convert(pre_parse_1: bool, pre_parse_2: bool):
+    unit_1 = "cup"
+    unit_2 = "pound"
+
+    uc = UnitConverter()
+    if pre_parse_1:
+        unit_1 = uc.parse(unit_1)
+    if pre_parse_2:
+        unit_2 = uc.parse(unit_2)
+
+    assert not uc.can_convert(unit_1, unit_2)
+
+
+def test_cannot_convert_invalid_unit():
+    uc = UnitConverter()
+    assert not uc.can_convert("cup", random_string())
+    assert not uc.can_convert(random_string(), "cup")
+
+
+def test_can_convert_same_unit():
+    uc = UnitConverter()
+    assert uc.can_convert("cup", "cup")
+
+
+def test_can_convert_volume_ounce():
+    uc = UnitConverter()
+    assert uc.can_convert("ounce", "cup")
+    assert uc.can_convert("cup", "ounce")
+
+
+def test_convert_simple():
+    uc = UnitConverter()
+    quantity, unit = uc.convert(1, "cup", "pint")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "pint"
+    assert quantity == 1 / 2
+
+
+@pytest.mark.parametrize("pre_parse_1", [True, False])
+@pytest.mark.parametrize("pre_parse_2", [True, False])
+def test_convert_pre_parsed(pre_parse_1: bool, pre_parse_2: bool):
+    unit_1 = "cup"
+    unit_2 = "pint"
+
+    uc = UnitConverter()
+    if pre_parse_1:
+        unit_1 = uc.parse(unit_1)
+    if pre_parse_2:
+        unit_2 = uc.parse(unit_2)
+
+    quantity, unit = uc.convert(1, unit_1, unit_2)
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "pint"
+    assert quantity == 1 / 2
+
+
+def test_convert_weight():
+    uc = UnitConverter()
+    quantity, unit = uc.convert(16, "ounce", "pound")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "pound"
+    assert quantity == 1
+
+
+def test_convert_zero_quantity():
+    uc = UnitConverter()
+    quantity, unit = uc.convert(0, "cup", "pint")
+
+    assert isinstance(unit, pint.Unit)
+    assert quantity == 0
+
+
+def test_convert_invalid_unit():
+    uc = UnitConverter()
+
+    with pytest.raises(UnitNotFound):
+        uc.convert(1, "pound", random_string())
+
+
+def test_convert_incompatible_units():
+    uc = UnitConverter()
+
+    with pytest.raises(pint.errors.DimensionalityError):
+        uc.convert(1, "pound", "cup")
+
+
+def test_convert_volume_ounce():
+    uc = UnitConverter()
+    quantity, unit = uc.convert(8, "ounce", "cup")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "cup"
+    assert quantity == 1
+
+
+def test_merge_same_unit():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(1, "cup", 2, "cup")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "cup"
+    assert quantity == 3
+
+
+@pytest.mark.parametrize("pre_parse_1", [True, False])
+@pytest.mark.parametrize("pre_parse_2", [True, False])
+def test_merge_compatible_units(pre_parse_1: bool, pre_parse_2: bool):
+    unit_1 = "cup"
+    unit_2 = "pint"
+
+    uc = UnitConverter()
+    if pre_parse_1:
+        unit_1 = uc.parse(unit_1)
+    if pre_parse_2:
+        unit_2 = uc.parse(unit_2)
+
+    quantity, unit = uc.merge(1, unit_1, 1, unit_2)
+    assert isinstance(unit, pint.Unit)
+    # 1 cup + 1 pint = 1 cup + 2 cups = 3 cups
+    assert quantity == 3
+
+
+def test_merge_weight_units():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(8, "ounce", 8, "ounce")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "ounce"
+    assert quantity == 16
+
+
+def test_merge_different_weight_units():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(1, "pound", 8, "ounce")
+
+    assert isinstance(unit, pint.Unit)
+    # 1 pound + 8 ounces = 16 ounces + 8 ounces = 24 ounces
+    assert str(unit) == "pound"
+    assert quantity == 1.5
+
+
+def test_merge_zero_quantities():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(0, "cup", 1, "cup")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "cup"
+    assert quantity == 1
+
+
+def test_merge_invalid_unit():
+    uc = UnitConverter()
+
+    with pytest.raises(UnitNotFound):
+        uc.merge(1, "pound", 1, random_string())
+
+
+def test_merge_incompatible_units():
+    uc = UnitConverter()
+
+    with pytest.raises(pint.errors.DimensionalityError):
+        uc.merge(1, "pound", 1, "cup")
+
+
+def test_merge_negative_quantity():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(-1, "cup", 2, "cup")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "cup"
+    assert quantity == 1
+
+
+def test_merge_volume_ounce():
+    uc = UnitConverter()
+    quantity, unit = uc.merge(4, "ounce", 1, "cup")
+
+    assert isinstance(unit, pint.Unit)
+    assert str(unit) == "fluid_ounce"  # converted automatically from ounce
+    assert quantity == 12
+
+
+def test_merge_quantity_and_unit_simple():
+    unit_1 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+    unit_2 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+
+    quantity, unit = merge_quantity_and_unit(1, unit_1, 2, unit_2)
+
+    assert quantity == 3
+    assert unit.name == "mealie_cup"
+
+
+def test_merge_quantity_and_unit_invalid():
+    unit_1 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+    unit_2 = CreateIngredientUnit(name="mealie_random", standard_quantity=1, standard_unit=random_string())
+
+    with pytest.raises(UnitNotFound):
+        merge_quantity_and_unit(1, unit_1, 1, unit_2)
+
+
+def test_merge_quantity_and_unit_compatible():
+    unit_1 = CreateIngredientUnit(name="mealie_pint", standard_quantity=1, standard_unit="pint")
+    unit_2 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+
+    quantity, unit = merge_quantity_and_unit(1, unit_1, 1, unit_2)
+
+    # 1 pint + 1 cup = 2 pints + 1 cup = 3 cups, converted to pint = 1.5 pint
+    assert quantity == 1.5
+    assert unit.name == "mealie_pint"
+
+
+def test_merge_quantity_and_unit_selects_larger_unit():
+    unit_1 = CreateIngredientUnit(name="mealie_pint", standard_quantity=1, standard_unit="pint")
+    unit_2 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+
+    quantity, unit = merge_quantity_and_unit(2, unit_1, 4, unit_2)
+
+    # 2 pint + 4 cup = 4 cups + 4 cups = 8 cups, should be returned as pint (larger unit)
+    assert quantity == 4
+    assert unit.name == "mealie_pint"
+
+
+def test_merge_quantity_and_unit_selects_smaller_unit():
+    unit_1 = CreateIngredientUnit(name="mealie_pint", standard_quantity=1, standard_unit="pint")
+    unit_2 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+
+    quantity, unit = merge_quantity_and_unit(0.125, unit_1, 0.5, unit_2)
+
+    # 0.125 pint + 0.5 cup = 0.25 cup + 0.5 cup = 0.75 cup, should be returned as cup (smaller for < 1)
+    assert quantity == 0.75
+    assert unit.name == "mealie_cup"
+
+
+def test_merge_quantity_and_unit_missing_standard_data():
+    unit_1 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+    unit_2 = CreateIngredientUnit(name="mealie_cup_no_std", standard_quantity=None, standard_unit=None)
+
+    with pytest.raises(ValueError):
+        merge_quantity_and_unit(1, unit_1, 1, unit_2)
+
+
+def test_merge_quantity_and_unit_volume_ounce():
+    unit_1 = CreateIngredientUnit(name="mealie_oz", standard_quantity=1, standard_unit="ounce")
+    unit_2 = CreateIngredientUnit(name="mealie_cup", standard_quantity=1, standard_unit="cup")
+
+    quantity, unit = merge_quantity_and_unit(8, unit_1, 1, unit_2)
+
+    assert quantity == 2
+    assert unit.name == "mealie_cup"
diff --git a/tests/unit_tests/repository_tests/test_unit_repository.py b/tests/unit_tests/repository_tests/test_unit_repository.py
index d2a0b7dfe..e48168131 100644
--- a/tests/unit_tests/repository_tests/test_unit_repository.py
+++ b/tests/unit_tests/repository_tests/test_unit_repository.py
@@ -1,11 +1,26 @@
 from uuid import UUID
 
+import pytest
+from sqlalchemy.orm import Session
+
+from mealie.repos.all_repositories import AllRepositories, get_repositories
 from mealie.schema.recipe.recipe import Recipe
 from mealie.schema.recipe.recipe_ingredient import RecipeIngredient, SaveIngredientUnit
-from tests.utils.factories import random_string
+from mealie.schema.user.user import GroupBase
+from tests.utils.factories import random_int, random_string
 from tests.utils.fixture_schemas import TestUser
 
 
+@pytest.fixture()
+def unique_local_group_id(unfiltered_database: AllRepositories) -> str:
+    return str(unfiltered_database.groups.create(GroupBase(name=random_string())).id)
+
+
+@pytest.fixture()
+def unique_db(session: Session, unique_local_group_id: str) -> AllRepositories:
+    return get_repositories(session, group_id=unique_local_group_id)
+
+
 def test_unit_merger(unique_user: TestUser):
     database = unique_user.repos
     recipe: Recipe | None = None
@@ -51,3 +66,79 @@ def test_unit_merger(unique_user: TestUser):
 
     for ingredient in recipe.recipe_ingredient:
         assert ingredient.unit.id == unit_1.id  # type: ignore
+
+
+@pytest.mark.parametrize("standard_field", ["name", "plural_name", "abbreviation", "plural_abbreviation"])
+@pytest.mark.parametrize("use_bulk", [True, False])
+def test_auto_inject_standardization(unique_db: AllRepositories, standard_field: str, use_bulk: bool):
+    unit_in = SaveIngredientUnit(name=random_string(), group_id=unique_db.group_id).model_dump()
+    unit_in[standard_field] = "gallon"
+
+    if use_bulk:
+        out_many = unique_db.ingredient_units.create_many([unit_in])
+        assert len(out_many) == 1
+        unit_out = out_many[0]
+    else:
+        unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_unit == "cup"
+    assert unit_out.standard_quantity == 16
+
+
+def test_dont_auto_inject_random(unique_db: AllRepositories):
+    unit_in = SaveIngredientUnit(name=random_string(), group_id=unique_db.group_id)
+    unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_quantity is None
+    assert unit_out.standard_unit is None
+
+
+def test_auto_inject_other_language(unique_db: AllRepositories):
+    # Inject custom unit map
+    GALLON = random_string()
+    unique_db.ingredient_units._standardized_unit_map = {GALLON: "gallon"}
+
+    # Create unit with translated value
+    unit_in = SaveIngredientUnit(name=GALLON, group_id=unique_db.group_id)
+    unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_unit == "cup"
+    assert unit_out.standard_quantity == 16
+
+
+@pytest.mark.parametrize("name", ["custom-mealie-unit", "gallon"])
+def test_user_standardization(unique_db: AllRepositories, name: str):
+    unit_in = SaveIngredientUnit(
+        name=name,
+        group_id=unique_db.group_id,
+        standard_quantity=random_int(1, 10),
+        standard_unit=random_string(),
+    )
+    unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_quantity == unit_in.standard_quantity
+    assert unit_out.standard_unit == unit_in.standard_unit
+
+
+def test_ignore_incomplete_standardization(unique_db: AllRepositories):
+    unit_in = SaveIngredientUnit(
+        name=random_string(),
+        group_id=unique_db.group_id,
+        standard_quantity=random_int(1, 10),
+        standard_unit=None,
+    )
+    unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_quantity is None
+    assert unit_out.standard_unit is None
+
+    unit_in = SaveIngredientUnit(
+        name=random_string(),
+        group_id=unique_db.group_id,
+        standard_quantity=None,
+        standard_unit=random_string(),
+    )
+    unit_out = unique_db.ingredient_units.create(unit_in)
+
+    assert unit_out.standard_quantity is None
+    assert unit_out.standard_unit is None
diff --git a/tests/unit_tests/services_tests/backup_v2_tests/test_backup_v2.py b/tests/unit_tests/services_tests/backup_v2_tests/test_backup_v2.py
index 754b632fa..22f25d33d 100644
--- a/tests/unit_tests/services_tests/backup_v2_tests/test_backup_v2.py
+++ b/tests/unit_tests/services_tests/backup_v2_tests/test_backup_v2.py
@@ -217,6 +217,22 @@ def _b9e516e2d3b3_add_household_to_recipe_last_made_household_to_foods_and_tools
                 assert not tool.households_with_tool
 
 
+def _a39c7f1826e3_add_unit_standardization_fields(session: Session):
+    groups = session.query(Group).all()
+
+    for group in groups:
+        # test_data.backup_version_1d9a002d7234_1 has a non-anonymized "pint" unit
+        # and has not yet run the standardization migration.
+        pint_units = (
+            session.query(IngredientUnitModel)
+            .filter(IngredientUnitModel.group_id == group.id, IngredientUnitModel.name == "pint")
+            .all()
+        )
+        for unit in pint_units:
+            assert unit.standard_quantity == 2
+            assert unit.standard_unit == "cup"
+
+
 def test_database_restore_data():
     """
     This tests real user backups to make sure the data is restored correctly. The data has been anonymized, but
@@ -227,6 +243,7 @@ def test_database_restore_data():
     """
 
     backup_paths = [
+        test_data.backup_version_1d9a002d7234_1,
         test_data.backup_version_44e8d670719d_1,
         test_data.backup_version_44e8d670719d_2,
         test_data.backup_version_44e8d670719d_3,
@@ -245,6 +262,7 @@ def test_database_restore_data():
         _d7c6efd2de42_migrate_favorites_and_ratings_to_user_ratings,
         _86054b40fd06_added_query_filter_string_to_cookbook_and_mealplan,
         _b9e516e2d3b3_add_household_to_recipe_last_made_household_to_foods_and_tools,
+        _a39c7f1826e3_add_unit_standardization_fields,
     ]
 
     settings = get_app_settings()
diff --git a/uv.lock b/uv.lock
index fd203f486..265499e65 100644
--- a/uv.lock
+++ b/uv.lock
@@ -850,6 +850,7 @@ dependencies = [
     { name = "paho-mqtt" },
     { name = "pillow" },
     { name = "pillow-heif" },
+    { name = "pint" },
     { name = "pydantic" },
     { name = "pydantic-settings" },
     { name = "pyhumps" },
@@ -923,6 +924,7 @@ requires-dist = [
     { name = "paho-mqtt", specifier = "==1.6.1" },
     { name = "pillow", specifier = "==12.1.1" },
     { name = "pillow-heif", specifier = "==1.3.0" },
+    { name = "pint", specifier = ">=0.25" },
     { name = "psycopg2-binary", marker = "extra == 'pgsql'", specifier = "==2.9.11" },
     { name = "pydantic", specifier = "==2.12.5" },
     { name = "pydantic-settings", specifier = "==2.13.1" },