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.
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.
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.
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
A 750ml bottle of red, white or rose wine (ABV 13.5%) contains 10 units.
See the guide below to find out how many units are in your favourite tipple.
*Gin, rum, vodka, whisky, tequila, sambuca. Large (35ml) single measures of spirits are 1.4 units.