Alcohol Units Calculator
Work out UK alcohol units from any drink — pint, glass of wine, spirit, cocktail — using the official NHS formula, and see how it compares to the Chief Medical Officers’ 14-unit weekly low-risk guideline.
Total UK alcohol units
2.84
- Units per drink
- 2.84
- Share of UK weekly low-risk limit (14 units)
- 20.3%
- Pure alcohol (grams)
- 22.7
A UK alcohol unit is 10 ml — or 8 g — of pure ethanol. Units are calculated as ABV% multiplied by the volume in millilitres, divided by 1,000. The UK Chief Medical Officers’ low-risk guideline (2016) is no more than 14 units a week, spread over three or more days, for both men and women. The percent-of-limit figure compares your total against that 14-unit weekly ceiling.
How to use this calculator
Enter the volume of one drink in millilitres (568 for a UK pint, 175 for a standard glass of wine, 25 for a single spirit measure), the ABV percentage printed on the label, and how many of that drink you are counting. The calculator returns total UK alcohol units, units per drink, the grams of pure alcohol you are consuming, and your share of the UK weekly low-risk limit of 14 units. Repeat for each different drink and add the totals if you are working out a session or a week.
How the calculation works
The NHS formula is: ABV percent × volume in millilitres ÷ 1,000 = units. One UK unit is defined as 10 ml — or 8 grams — of pure ethanol, which is roughly how much an average adult liver clears in an hour. The 14-unit weekly cap is the Chief Medical Officers’ Low Risk Drinking Guideline published in 2016 and applies equally to men and women; the guideline also advises spreading drinking over three or more days and having several drink-free days each week. Different countries define a unit differently — Australia uses 10 g, the US uses 14 g — so always use the UK definition for guidance issued by the UK government.
Worked example
A pint of strong lager is 568 ml at 5.2% ABV. Units = 5.2 × 568 ÷ 1,000 = 2.95, which rounds to about 3 units. Four pints in an evening is roughly 12 units — already 86% of the 14-unit weekly low-risk limit in one sitting. A standard 175 ml glass of 12% wine is 2.1 units; a 750 ml bottle of 13.5% wine is 10.1 units; a 25 ml single shot of 40% spirit is exactly 1 unit. Each UK unit contains 8 grams of pure alcohol, so three pints equate to about 24 grams of ethanol.
Frequently asked questions
What is the UK alcohol units formula?
Units equal ABV percentage multiplied by volume in millilitres, divided by 1,000. So a 568 ml pint at 5% is 5 × 568 ÷ 1,000 = 2.84 units. This is the official NHS calculation and it is the same regardless of drink type — beer, wine, spirits, cider or cocktails. A UK unit corresponds to 10 ml (or 8 g) of pure ethanol.
How many units is a pint of lager?
It depends on the strength. A 568 ml UK pint at 3.6% ABV (a typical bitter or weak lager) is about 2 units. A pint at 5% (most mainstream lagers like Stella, Heineken or Foster's) is 2.84 units. A pint at 5.6% (Carlsberg Special Brew or many craft IPAs) is about 3.2 units. Strong continental lagers and craft beers can push 6%+, taking a single pint over 3.4 units.
How many units is a glass of wine?
A standard small glass of wine (125 ml) at 12% ABV is 1.5 units. A standard medium glass (175 ml) at 12% is 2.1 units. A large glass (250 ml) at 13% is 3.25 units — a third of a bottle. A 750 ml bottle of 13.5% wine is 10.1 units, so two people sharing one bottle take 5 units each. Stronger reds and fortified wines (15%+) push these numbers up by a fifth or more.
What is the UK weekly limit for alcohol?
The UK Chief Medical Officers’ Low Risk Drinking Guideline, published in 2016, is to drink no more than 14 units per week on a regular basis. This applies to both men and women — the gendered guidance from before 2016 was withdrawn after evidence showed similar risks at lower thresholds for both sexes. If you do drink up to 14 units, spread it across three or more days and have several alcohol-free days per week. There is no completely safe level of alcohol consumption; 14 units is a low-risk ceiling, not a target.
How long does alcohol take to leave your system?
The liver clears roughly one UK unit per hour for an average adult, though that varies with body size, sex, age and liver health. Three pints of 5% lager (about 8.5 units) takes around 8–9 hours to fully metabolise — which is why drinking late means you may still be legally over the drink-drive limit the next morning. The unit total here is a useful proxy for how long the alcohol will stick around: 6 units ≈ 6 hours, 12 units ≈ 12 hours, and so on, plus an hour or two for the last drink to be absorbed.
Are UK units the same as US standard drinks?
No. A UK unit is 8 g (10 ml) of pure ethanol. A US standard drink is 14 g (17.7 ml), so roughly 1.75 UK units. An Australian standard drink is 10 g, very close to but not identical to a UK unit. EU countries vary between 8 g (Netherlands, Austria) and 14 g (Italy). Always use the UK definition when comparing your drinking against UK guidance, and check the local definition when reading research or guidelines from elsewhere.