# 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).

- Calculator id: `standard-drinks` · Category: Health (`health`) · Tool name: `calculate_standard_drinks`
- Canonical page: https://tttkmbb.com/health/standard-drinks · This document: https://tttkmbb.com/health/standard-drinks.md · JSON definition: https://tttkmbb.com/health/standard-drinks.json

## Purpose

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).

**Use when:** 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.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `volume_ml` | number | mL | required | Volume of one serving in millilitres (330 mL can, 568 mL UK pint, 150 mL wine glass, 44 mL US shot). (> 0, max 5000) |
| `abv_percent` | number | % | required | Alcohol strength in percent by volume (ABV), e.g. 5 for lager, 13.5 for wine, 40 for spirits. (min 0, max 100) |
| `servings` | number |  | optional, default 1 | Number of servings consumed. (> 0, max 100) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `alcohol_grams` | number | g | Grams of ethanol in all servings (alcohol_ml × 0.789). |
| `alcohol_ml` | number | mL | Millilitres of ethanol in all servings. |
| `standard_drinks_us` | number |  | Alcohol grams / 14 (NIAAA definition). |
| `standard_drinks_au` | number |  | Alcohol grams / 10 (NHMRC definition). |
| `units_uk` | number |  | volume_ml × abv_percent / 1000 × servings (NHS formula; 1 unit = 10 mL ≈ 8 g of alcohol). |
| `standard_drinks_eu_who` | number |  | Alcohol grams / 10; the WHO reference definition, also used by many European countries (national definitions range from 8 to 20 g). |
| `standard_drinks_canada` | number |  | Alcohol grams / 13.45 (17.05 mL of ethanol). |
| `standard_drinks_japan` | number |  | Alcohol grams / 20. |
| `calories_from_alcohol` | number | kcal | Alcohol grams × 7 kcal; excludes sugars and other carbohydrates in the drink. |

## 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.

## Data Sources

- NIAAA – What Is a Standard Drink? — https://www.niaaa.nih.gov/alcohols-effects-health/overview-alcohol-consumption/what-standard-drink (government, retrieved 2026-09-24)
- NHMRC – Australian guidelines to reduce health risks from drinking alcohol — https://www.nhmrc.gov.au/health-advice/alcohol (government, retrieved 2026-09-24)
- NHS – Alcohol units — https://www.nhs.uk/live-well/alcohol-advice/calculating-alcohol-units/ (government, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/standard-drinks?volume_ml=…&abv_percent=…`
- `POST https://tttkmbb.com/api/v1/calculate/standard-drinks` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/standard-drinks · OpenAPI operationId `calculate_standard_drinks` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "standard-drinks", "inputs": {…}}`

## Example

- 500 mL beer at 5 %: inputs `{"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 %: inputs `{"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
```

## Limitations

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. 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. All values are computed from the formula above; no measurement or live data is involved.

## 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.

## Related

- [Blood Alcohol Content Calculator](https://tttkmbb.com/health/bac-widmark.md) — Estimate blood alcohol concentration from the number of standard drinks.
- [TDEE Calculator](https://tttkmbb.com/health/tdee.md) — See how the alcohol calories compare with daily energy needs.