What are units of alcohol?
The alcoholic content of a drink is measured in units. For example, a pint of typical-strength lager contains just over 2 units, while a glass of wine can contain from around 1.5 to over 3 units, depending on its size and strength.
One unit measures the amount of alcohol the average adult's body can process in an hour – after which there should be no alcohol left in their bloodstream. However, this figure of an hour is only an average. It can vary depending on someone's weight and size, their gender and their age. Young people tend to process alcohol more slowly than adults.
Units are also used as a measure of what is regarded as a safe daily amount for adults to drink. The NHS advise that men should not regularly drink more than 3-4 four units a day and women not more than 2-3.
What's a safe amount for young people to drink?
According to expert health advice from the government and leading doctors, children and young people are advised that an alcohol-free childhood is the healthiest and best option. They recommend that if young people do drink alcohol, it should not be until at least the age of 15 years. In this case, it should be no more than once a week, and should never exceed the recommended daily limits for adults.
Find out more about how many units are contained in the example drinks below, but be aware that this will vary depending on the size of the drink and its actual strength.
Beer and lager
Wine and champagne
One way of calculating your units is to multiply the drink volume (ml) by strength (%), and then dividing by 1000. For example, with the small glass of wine above, multiplying 125 (volume in ml) by 12 (strength in %), gives 1.5 units.
Because drinks come in all shapes and sizes, it can be tricky to keep track of your units. Try out the NHS units calculator to help you add them up.
Or you can download the NHS desktop alcohol tracker. It can calculate alcohol units, keep a personal drinks diary on your desktop and provide feedback on your drinking over time.
If you have an iPhone or iPod touch you can download the free NHS Drinks Tracker from the app store straight from your phone. It allows you to keep a drink diary and get feedback on your drinking.