What is a unit of alcohol?

What's a Unit?

Alcohol in the UK is measured in 'units'. One unit of alcohol equals about 10ml or 8g of pure ethanol, which is the amount of alcohol the liver can process in an hour.

Most drinks now are labelled with the number of units - look on the back of the can or bottle.

Stronger drinks will have more units so you can lower your total unit intake just by drinking lower-strength beer, cider and wine.  The stronger and larger the drink, the more units you'll be drinking.

  • Half pint of (5% abv) lager - 1.5 units
  • Pint of (5% abv) lager - 3 units
  • Large glass of wine (12% abv) - 3 units
  • Bottle of (12%) wine - 10 units

The UK NHS guide for lower-risk drinking is to drink no more than 14 units per week - so that could be 4-5 pints of lager or large glasses of wine, per week. 

% alcohol by volume

All alcoholic drinks by law must be labelled with the % alcohol by volume (abv) which represents the strength of the drink. The higher the %, the stronger the drink. 

You can work out how many units there are in any drink by multiplying the total volume of a drink (in ml) by its ABV (%) and dividing the result by 1,000.

For example, to work out the number of units in a pint (568ml) of strong lager (ABV 5.2%):

5.2 (%) x 568 (ml) ÷ 1,000 = 2.95 units.