Alcohol units

We're supposed to be keeping an eye on how much we drink, but how many of us really know what a unit of alcohol is?

With so many different drinks and glass sizes, from shots to pints – not to mention bottles – it's easy to get confused about how many units are in your drink.

  • Use the units calculator to quickly calculate units in your favourite drink. 
  • Download a drinks diary (PDF, 656kb) to track your drinking over a week.

The idea of counting alcohol units was first introduced in the UK in 1987 to help people keep track of their drinking.

Units are a simple way of expressing the quantity of pure alcohol in a drink. One unit equals 10ml or 8g of pure alcohol, which is around the amount of alcohol the average adult can process in an hour. This means that within an hour there should be, in theory, little or no alcohol left in the blood of an adult, although this will vary from person to person.

The number of units in a drink is based on the size of the drink as well as its alcohol strength. For example, a pint of strong lager contains 3 units of alcohol, whereas the same volume of standard lager has just over 2 units.

Calculating units

Using units is a simpler way of representing a drink's alcohol content, which is usually expressed by the standard measure ABV, which stands for alcohol by volume.

ABV is a measure of the amount of pure alcohol as a percentage of the total volume of liquid in a drink.

The NHS recommends:

  • Men should not regularly drink more than 3-4 units of alcohol a day
  • Women should not regularly drink more than 2-3 units a day

'Regularly' means drinking this amount every day or most days of the week.

You can find the ABV on the labels of cans and bottles, sometimes written as "vol" or "alcohol volume" or you can ask bar staff about particular drinks.

For example, wine that says "12% ABV" or "alcohol volume 12%" means that 12% of the volume of that drink is pure alcohol.

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 (which is measured as a percentage) and dividing the result by 1,000.

  • Strength (ABV) x Volume (ml) ÷ 1,000 = units.

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

To make things easier, use the units calculator to quickly calculate units and download a drinks tracker to your phone to keep on top of your drinking and get personalised feedback.

Drinks and units

 

*Gin, rum, vodka, whisky, tequila, sambuca. Large (35ml) single measures of spirits are 1.4 units.

Last reviewed: 26/04/2011

Next review due: 26/04/2012

Ratings

How helpful is this page?

Average rating

Based on 7 ratings

All ratings

Add your rating

Tools

Alcohol units calculator

Use this alcohol unit calculator to find out how many units there are in a single drink or in a number of drinks.

Alcohol myth buster

Drinks diary

How much are you drinking? Keep a drinks diary for a week to find out.

Drinking and alcohol

Calculate your units, read about the health risks of drinking too much and find out where to get help and support.