Units and strength
A unit is a way of measuring how much pure alcohol is in a drink. The size of the drink matters, but so does its strength. Two drinks that look the same can contain very different amounts of alcohol.
What a unit means One unit is 10ml or 8g of pure alcohol.
Units make it possible to compare drinks of different sizes and strengths. The number of units depends on both the amount you drink and the percentage of alcohol in it.
You can work out the units in a drink with this calculation:
Volume in ml × ABV ÷ 1000 = units
For example, a 500ml drink at 5% ABV contains 2.5 units.
What ABV means ABV tells you what percentage of the drink is alcohol.
ABV means alcohol by volume. A drink marked 5% ABV contains more alcohol than the same-sized drink at 3.5% ABV.
The difference can look small on the label but add up quickly over several drinks.
Check the bottle, can or menu rather than assuming all beer, cider, wine or spirits are roughly the same strength.
What common drinks contain The same drink can contain more or fewer units depending on its size and strength.
A pint of 4% beer is about 2.3 units.
A pint of 5% beer is about 2.8 units.
A 175ml glass of 12.5% wine is about 2.2 units.
A 250ml glass of 12.5% wine is about 3.1 units.
A 750ml bottle of 13% wine is about 9.8 units.
A 25ml measure of 40% spirits is 1 unit.
A 50ml double measure of 40% spirits is 2 units.
Home measures can be much bigger A glass poured at home may contain far more alcohol than you think.
Spirits poured by eye can easily become doubles or more. Large wine glasses can hold 250ml or more, and topping up a glass makes it difficult to know how much has actually been drunk.
If you are trying to work out what you really drink, measure a usual home pour once rather than guessing.
The 14-unit guideline For both men and women, regularly drinking more than 14 units a week increases health risks.
UK Chief Medical Officers advise that, to keep health risks from alcohol at a low level, it is safest not to drink more than 14 units a week on a regular basis.
If you regularly drink as much as 14 units, it is better to spread them over three or more days rather than drinking most of them in one or two sessions.
Fourteen units is roughly six pints of 4% beer, six medium glasses of 12.5% wine, or seven double measures of 40% spirits.
NHS Inform — alcohol units and drinking guidelines ↗Units do not tell the whole story How and why you drink matters as well as the weekly total.
Two people can drink the same number of units and have very different problems. Drinking quickly, blacking out, drinking first thing in the morning, hiding alcohol, needing alcohol to feel normal or being unable to stop are all important regardless of the total.
Read Is my drinking a problem? → Read about alcohol dependence →If your total is higher than you expected Knowing the number is useful only if you know what to do with it.
If working out your units has made you concerned about your drinking, speak to your GP, Drinkline Scotland or a local alcohol service.
If you drink heavily every day, get shakes, sweating or anxiety when alcohol wears off, or need alcohol to feel normal, do not suddenly stop without medical advice because withdrawal can be dangerous.
Drinkline Scotland — 0800 7314 314 Call Find alcohol support and local services in Scotland ↗ Read about alcohol withdrawal →