Alcohol Units Calculator

Alcohol units are calculated with a single formula: volume in millilitres multiplied by ABV as a percentage, divided by 1,000. One unit equals 10 ml, or 8 g, of pure alcohol. That makes a standard 175 ml glass of 12% wine 2.1 units, a pint of 4% lager 2.3 units, and a 25 ml measure of 40% spirits exactly 1 unit. Stronger drinks climb quickly, so a pint of 5% craft beer is 2.8 units, a 175ml glass of 13% wine is 2.3, and a whole 750ml bottle of 13% wine comes to 9.75 units.

Measures vary more than most drinkers realise. A single shot is 25ml in England and Wales, though 35ml is common in clubs, and Scotland serves 25ml by default. Modern wines are stronger than the ones the old rules of thumb were built on, often 12.5 to 14% against 11% a generation ago, and pints frequently run 4.5 to 5.5%. The practical result is that actual units can be 30 to 50% higher than a rough mental estimate, which is why it helps to enter the drink type, volume and ABV rather than guessing.

The UK Chief Medical Officers advise no more than 14 units a week for both men and women, revised in 2016 down from 21 units for men, and spread over 3 or more days rather than taken in one go. Fourteen units is about 6 pints of 4% beer, 7 medium 175ml glasses of wine or 14 single measures of spirits. Binge drinking means more than 6 units for women or 8 for men in one session. The NHS advises no alcohol at all in pregnancy, and no level carries zero risk, though 14 is treated as low risk.

Drink-driving limits split the UK in two. England, Wales and Northern Ireland allow 80 mg of alcohol per 100 ml of blood, one of the highest limits in Europe. Scotland dropped to 50 mg per 100 ml in 2014. In practice, for a man of 75kg the England limit works out at roughly 3 to 4 units, about 2 pints of lager, while Scotland's is nearer 1.5 to 2 units, so a single pint. Tolerance varies with sex, weight, food and timing, and the morning after is routinely underestimated, since 6 or more units the previous evening can still be in the blood 8 hours later.

Alcohol is more calorific than people expect, at 7 kcal per gram against 4 for carbohydrate and 9 for fat. A pint of lager typically contains 180 to 230 kcal and a large glass of wine around 230. In detail, a pint of 4% lager is roughly 180 kcal and one of 5% craft beer nearer 250, a 175ml glass of red wine about 160 and a whole bottle around 625, which is a quarter of a day's intake. A double gin and tonic is about 200 kcal and a pina colada 480. Drinking 14 units a week adds 18,200 kcal a year, or 5lb, which is 2.4 kg, of weight gain if nothing else changes, and those calories are stored preferentially as visceral fat.

Risk climbs steadily with intake. Between 1 and 14 units a week is the low-risk band the CMOs describe. From 14 to 35 units the chances of high blood pressure, liver disease and several cancers including breast, throat, liver and colon all rise. From 35 to 50 units you are into liver inflammation, neurological problems and mental health effects, and above 50 units dependence is likely and severe liver damage probable. The NHS suggests 2 to 3 alcohol-free days a week to let the liver recover.

Cutting back shows results faster than most people assume. Liver enzymes normalise over 4 to 6 weeks of abstinence, which is why Dry January is more than a gesture, and sleep, mood and blood pressure improve within 2 weeks. Dependence, by contrast, develops gradually, and the signs are needing a drink to function, drinking before noon and hiding how much is going down. Drinkline is free on 0300 123 1110.