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Standard Drinks Calculator

Converts a beverage's volume and alcohol by volume into grams of pure alcohol (ethanol density 0.789 g/mL) and expresses it as standard drinks of the US (14 g), Australia and WHO/EU (10 g), Canada (13.45 g) and Japan (20 g), UK units (volume × ABV / 1000), and the calories from alcohol (7 kcal/g).

When to use

You need to count standard drinks or UK units for a drink of known size and strength, convert between national standard-drink definitions, or get the alcohol calories of a beverage.

Do not use when: You want an estimate of blood alcohol concentration (use bac-widmark) or the ABV of a cocktail; the result is informational only and must not be used to decide whether to drive.

Formula

alcohol_ml = volume_ml × abv_percent / 100 × servings; alcohol_grams = alcohol_ml × 0.789; standard_drinks_us = alcohol_grams / 14; standard_drinks_au = standard_drinks_eu_who = alcohol_grams / 10; standard_drinks_canada = alcohol_grams / 13.45; standard_drinks_japan = alcohol_grams / 20; units_uk = volume_ml × abv_percent / 1000 × servings; calories_from_alcohol = alcohol_grams × 7

Ethanol density 0.789 g/mL at 20 °C. National standard-drink sizes are conventions for counting, not physiological thresholds; results are informational and must not be used to decide whether to drive.

Inputs

ParameterTypeUnitRequiredDescription
volume_mlnumbermLyesVolume of one serving in millilitres (330 mL can, 568 mL UK pint, 150 mL wine glass, 44 mL US shot). Range: > 0, ≤ 5000
abv_percentnumber%yesAlcohol strength in percent by volume (ABV), e.g. 5 for lager, 13.5 for wine, 40 for spirits. Range: ≥ 0, ≤ 100
servingsnumberdefault 1Number of servings consumed. Range: > 0, ≤ 100

Outputs

OutputTypeUnitDescription
alcohol_gramsnumbergGrams of ethanol in all servings (alcohol_ml × 0.789).
alcohol_mlnumbermLMillilitres of ethanol in all servings.
standard_drinks_usnumberAlcohol grams / 14 (NIAAA definition).
standard_drinks_aunumberAlcohol grams / 10 (NHMRC definition).
units_uknumbervolume_ml × abv_percent / 1000 × servings (NHS formula; 1 unit = 10 mL ≈ 8 g of alcohol).
standard_drinks_eu_whonumberAlcohol grams / 10; the WHO reference definition, also used by many European countries (national definitions range from 8 to 20 g).
standard_drinks_canadanumberAlcohol grams / 13.45 (17.05 mL of ethanol).
standard_drinks_japannumberAlcohol grams / 20.
calories_from_alcoholnumberkcalAlcohol grams × 7 kcal; excludes sugars and other carbohydrates in the drink.

Example

500 mL beer at 5 %: {"volume_ml":500,"abv_percent":5} → {"alcohol_grams":19.73,"alcohol_ml":25,"standard_drinks_us":1.41,"standard_drinks_au":1.97,"units_uk":2.5,"standard_drinks_canada":1.47,"standard_drinks_japan":0.99,"calories_from_alcohol":138}

750 mL wine at 13.5 %: {"volume_ml":750,"abv_percent":13.5,"servings":1} → {"alcohol_grams":79.89,"standard_drinks_us":5.71,"standard_drinks_au":7.99,"units_uk":10.13,"calories_from_alcohol":559}

GET https://tttkmbb.com/api/v1/calculate/standard-drinks?volume_ml=500&abv_percent=5

Machine access

Sources

FAQ

Why is a UK unit not exactly 8 g?

A UK unit is defined as 10 mL of pure alcohol, which weighs 7.89 g; the NHS formula volume × ABV / 1000 gives units directly from the label.

Does 'servings' multiply everything?

Yes. All outputs are totals for servings × volume_ml, so enter the single-serving volume and the number of servings.

Are the calories the whole drink?

No, only the 7 kcal per gram of ethanol. Beer, sweet wine, cider and mixers add carbohydrate calories that this calculator does not know.

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