Alcohol Unit Calculator NHS

Use this independent UK alcohol unit calculator to estimate the units in a drink from its serving size and alcohol by volume (ABV). One UK unit is 10ml of pure alcohol.

Calculate alcohol units

How alcohol units are calculated

The standard UK formula is volume in millilitres × ABV ÷ 1,000 = units. ABV is the percentage of the drink that is pure alcohol. The formula means a 25ml spirit at 40% ABV contains 1 unit, while a 175ml glass of wine at 12% contains 2.1 units.

Worked example

A 568ml pint at 5% ABV contains 568 × 5 ÷ 1,000 = 2.84 units. Two such pints contain about 5.68 units.

UK weekly alcohol guidance

NHS guidance says men and women who drink most weeks should not regularly drink more than 14 units a week. If you drink as much as 14 units, spread drinking over 3 or more days. The NHS also advises several drink-free days when cutting down. There is no completely safe level of drinking.

If you are pregnant or think you could become pregnant, NHS advice says the safest approach is not to drink alcohol at all.

Important limitation

This calculator measures alcohol units only. It cannot calculate your blood alcohol concentration, tell you when alcohol has left your body, or tell you whether it is safe or legal to drive. Never use an alcohol-unit estimate to decide whether to drive.

If you have physical withdrawal symptoms such as shaking, sweating or feeling anxious until your first drink, NHS guidance says to get medical advice before stopping suddenly because withdrawal can be dangerous.

Authoritative sources

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FAQs

What is one unit of alcohol?

One UK unit equals 10ml or 8g of pure alcohol.

How many units are in a pint?

It depends on the pint’s ABV. A 568ml pint at 4% contains about 2.27 units; at 5% it contains about 2.84 units.

Is 14 units a safe limit?

It is described as a low-risk guideline, not a completely safe level. NHS guidance says not to regularly exceed 14 units a week if you drink most weeks.

Can this calculator tell me if I can drive?

No. Alcohol units cannot reliably determine blood alcohol level or fitness to drive.

Disclaimer: This independent calculator is for general information and is not medical advice or an official NHS tool.

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