What is a UK alcohol unit?

One UK unit = 8g (10ml) of pure alcohol. A pint of 5% beer contains about 2.8 units. A 175ml glass of 12% wine has 2.1 units. The UK Chief Medical Officers advise not regularly exceeding 14 units per week.

How do I calculate alcohol units?

Units = Volume (ml) × ABV% ÷ 1000. For example: 568ml pint at 5% ABV = 568 × 5 ÷ 1000 = 2.84 UK units. Or in the UK formula: (ABV% × volume in ml) ÷ 1000.

How does a UK unit differ from a US standard drink?

A UK unit = 8g of pure alcohol. A US standard drink = 14g of pure alcohol. A US drink is 1.75× larger than a UK unit. An Australian standard drink = 10g.

How long does it take to process one unit of alcohol?

The liver processes about 1 UK unit (8g) per hour — roughly one small drink per hour. Eating food, coffee, or time will not speed this up. BAC must fall on its own.

What BAC is the legal driving limit?

UK and US: 0.08% BAC. Most of Europe and Australia: 0.05% BAC. Scotland: 0.05% BAC. Some countries have zero tolerance. BAC estimates from this calculator are approximations — never drive after drinking.

Alcohol Unit Calculator

Calculate UK alcohol units, US standard drinks, and calories in any drink. Track weekly units vs the 14-unit UK guideline, estimate BAC, and compare driving limits by country.

Drink Type

Volume (ml) ?

ABV % ?

UK Units

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US Standard Drinks —

Calories —

Pure Alcohol —

Extended More scenarios, charts & detailed breakdown ▾

Volume (ml)

ABV %

UK Units

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US Standard Drinks —

AU Standard Drinks —

Calories —

Professional Full parameters & maximum detail ▾

Volume (ml)

ABV %

Country Standard

Body Weight (kg)

Sex

Standard Drinks by Country

Pure Alcohol —

UK Units (8g) —

US Standard Drinks (14g) —

AU Standard Drinks (10g) —

Health & Safety

Calories —

Peak BAC Estimate —

vs. Driving Limit —

Liver Processing Time —

Risk if Drunk Daily —

How to Use This Calculator

Select your drink type and enter the volume in ml.
Enter the ABV% from the label.
See UK units, US standard drinks, and calories.
Use the Session Tracker to log multiple drinks and estimate BAC.
Use the Weekly Log to check weekly units vs the 14-unit UK guideline.

Formula

Pure Alcohol (g) = Volume (ml) × ABV% ÷ 100 × 0.789

UK Units = Pure Alcohol (g) ÷ 8

US Standard Drinks = Pure Alcohol (g) ÷ 14

BAC estimate = (alcohol g ÷ 1000) ÷ (weight kg × r) × 100, where r = 0.68 male, 0.55 female

Example

Example: UK pint (568 ml) of 5% lager. Pure alcohol = 568 × 0.05 × 0.789 = 22.4g. UK units = 22.4 ÷ 8 = 2.8 units. US standard drinks = 22.4 ÷ 14 = 1.6. Calories ≈ 180.

Frequently Asked Questions

One UK unit = 8g (10ml) of pure alcohol. A pint of 5% beer contains about 2.8 units. A 175ml glass of 12% wine has 2.1 units. The UK Chief Medical Officers advise not regularly exceeding 14 units per week.
Units = Volume (ml) × ABV% ÷ 1000. For example: 568ml pint at 5% ABV = 568 × 5 ÷ 1000 = 2.84 UK units. Or in the UK formula: (ABV% × volume in ml) ÷ 1000.
A UK unit = 8g of pure alcohol. A US standard drink = 14g of pure alcohol. A US drink is 1.75× larger than a UK unit. An Australian standard drink = 10g.
The liver processes about 1 UK unit (8g) per hour — roughly one small drink per hour. Eating food, coffee, or time will not speed this up. BAC must fall on its own.
UK and US: 0.08% BAC. Most of Europe and Australia: 0.05% BAC. Scotland: 0.05% BAC. Some countries have zero tolerance. BAC estimates from this calculator are approximations — never drive after drinking.

Related Calculators

Sources & References (5) ▾

UK Chief Medical Officers — Low Risk Drinking Guidelines: You and Alcohol (2016) — UK Department of Health
NIAAA — Alcohol Facts and Statistics (2023) — NIAAA
WHO — Global status report on alcohol and health 2018 — World Health Organization
Alcohol Change UK — Alcohol units: what is a unit? — Alcohol Change UK
NHS — Alcohol units — NHS