How the alcohol units calculator works
A unit is 10ml (8g) of pure alcohol, about the amount an average adult's body can process in an hour. The number of units in any drink depends on how strong it is and how much of it there is. The NHS formula is:
units = strength (ABV %) × volume (ml) ÷ 1,000
So a pint (568ml) of 4% lager has 4 × 568 ÷ 1,000 = 2.3 units. The calculator works out each drink exactly from its strength and size, adds them up for the week and compares the total with the NHS guideline.
The NHS guideline: 14 units a week
The UK Chief Medical Officers advise that men and women shouldn't regularly drink more than 14 units a week. If you do drink as much as 14 units, it's best to spread it evenly over three or more days rather than saving it up for one or two heavy sessions, and to have several drink-free days each week. There is no completely safe level of drinking; 14 units is the level at which the risks are kept low.
If you're pregnant or think you could become pregnant, the safest approach is not to drink alcohol at all.
How many units are in a drink?
| Drink | Strength | Units |
|---|---|---|
| Single spirit, 25ml | 40% | 1 |
| Large single spirit, 35ml | 40% | 1.4 |
| Alcopop, 275ml | 4.6% | 1.3 |
| Bottle of beer, 330ml | 5% | 1.7 |
| Small glass of wine, 125ml | 12% | 1.5 |
| Standard glass of wine, 175ml | 12% | 2.1 |
| Pint of lower-strength beer or cider | 3.6% | 2 |
| Pint of 4% beer or lager | 4% | 2.3 |
| Can of lager or cider, 440ml | 5.5% | 2.4 |
| Pint of strong lager or cider | 5.2% | 3 |
| Large glass of wine, 250ml | 12% | 3 |
| Bottle of wine, 750ml | 12% | 9 |
Many wines are stronger than 12%. A 750ml bottle of 13.5% red has 10.1 units, so a large glass of it is 3.4 units. Use "Add your own drink" for anything that isn't listed.
Worked example
Four pints of 4% lager and two standard glasses of wine in a week:
- Lager: 4 × (4 × 568 ÷ 1,000) = 4 × 2.27 = 9.1 units
- Wine: 2 × (12 × 175 ÷ 1,000) = 2 × 2.1 = 4.2 units
- Total: 13.3 units, just under the 14-unit guideline
Swap the wine for a large glass every night of the week and the total is 21 units, seven over the guideline.
Tips for cutting down
- Choose smaller measures. A 125ml glass of wine instead of a 250ml one halves the units.
- Check the strength. Switching from a 5.2% lager to a 3.6% one cuts the units in a pint by about a third.
- Have drink-free days. Pick a few days each week when you don't drink at all.
- Alternate with water or soft drinks on a night out, and try alcohol-free beers and wines (0.5% or less).
- Watch home measures. Drinks poured at home are often much bigger than pub measures.
Alcohol also contains a lot of calories. If you're trying to lose weight, our calorie calculator shows how many calories you need a day, and the BMI calculator checks whether you're a healthy weight.
If you're worried about how much you drink, speak to your GP. You can also call Drinkline free on 0300 123 1110 for confidential advice.
Frequently asked questions
How many units are in a pint?
A pint of 4% beer or lager has about 2.3 units. A pint of lower-strength (3.6%) beer has 2 units and a pint of strong (5.2%) lager or cider has about 3 units.
How many units are in a bottle of wine?
A 750ml bottle of 12% wine has 9 units. At 13.5%, which is common for red wine, it's just over 10 units, so one bottle alone is more than two-thirds of the weekly guideline.
What is the weekly limit for alcohol in the UK?
The NHS advises men and women not to regularly drink more than 14 units a week, spread over three or more days, with several drink-free days.
How many units is a double vodka?
A double (50ml) measure of 40% vodka, gin, rum or whisky is 2 units. A large double of 70ml is 2.8 units.
How long does it take for a unit of alcohol to leave your body?
As a rough guide, the body processes about one unit an hour, but this varies a lot between people. There's no way to speed it up, so don't drive the morning after a heavy night.
Last reviewed October 2026 using 2026/27 figures. This calculator gives an estimate for guidance only.