Alcohol Units Calculator
Free alcohol units calculator. Enter any drink's size and ABV to get UK units, US standard drinks, grams of pure alcohol, calories, and an estimated time to metabolize.
Alcohol Units Calculator
Measurement
Pick a drink
Your drink
Editing the size or ABV switches the preset to Custom.
Standard drink basis
UK units are always shown, whichever basis you pick.
Weekly pattern
Calories count the ethanol only, at 7 kcal per gram. They exclude carbohydrate, residual sugar, and mixers, so for beer, cider, sweet wine, and cocktails treat this as a floor rather than a total.
The metabolism figure is a rough average of about 1 unit per hour. It is not a blood alcohol reading and must never be used to judge whether you are fit to drive or operate machinery.
At this rate, per week
UK Chief Medical Officers advise no more than 14 units a week for men and women alike, spread over three or more days.
About 0 lb of stored fat at 3,500 kcal per pound.
Drinking at this level is worth a conversation with a GP or doctor. In the US, the NIAAA Alcohol Treatment Navigator is a free place to start.
Estimates only, for general information rather than medical advice. Alcohol affects everyone differently. If you are pregnant, taking medication, managing a health condition, or worried about your drinking, talk to a doctor.
How to calculate alcohol units and standard drinks
UK units and US standard drinks measure the same thing (the amount of pure ethanol in your glass) using two different yardsticks. Both start from volume and ABV.
UK alcohol units
units = (volume in ml x ABV%) / 1,000A 568 ml pint at 5.2% ABV: 568 x 5.2 / 1,000 = 2.95 units
US standard drinks
grams of alcohol = volume in ml x (ABV% / 100) x 0.789
standard drinks = grams / 14A 355 ml (12 oz) can at 5% ABV: 355 x 0.05 x 0.789 = 14.0 g, which is 1.0 standard drink
The 0.789 in the middle is the density of ethanol at 20 degrees Celsius, which turns millilitres of alcohol into grams. Most calculators skip it. It also explains why the NIAAA examples come out so even: 12 oz of 5% beer, 5 oz of 12% wine, and 1.5 oz of 40% spirits all land on 14 g, one US standard drink each.
One drink gives two answers because the UK counts 8 g of alcohol per unit while the US counts 14 g per standard drink. A 568 ml pint of 4% lager is 2.3 UK units and 1.3 US standard drinks at the same time. The quick conversion: 1 US standard drink is about 1.75 UK units. Other countries sit in between, with Australia and most of the EU at 10 g and Canada at 13.6 g.
Units and calories in common drinks
Every row below uses the formulas above. Calories are from the alcohol only.
| Serving | ABV | UK units | US standard drinks | Calories from alcohol |
|---|---|---|---|---|
| Pint of beer (568 ml) | 4% | 2.3 | 1.3 | 125 kcal |
| Strong pint / IPA (568 ml) | 5.2% | 3.0 | 1.7 | 163 kcal |
| Beer can, US (355 ml) | 5% | 1.8 | 1.0 | 98 kcal |
| Bottled beer (330 ml) | 4.5% | 1.5 | 0.8 | 82 kcal |
| Small wine glass (125 ml) | 12% | 1.5 | 0.8 | 83 kcal |
| Medium wine glass (175 ml) | 12% | 2.1 | 1.2 | 116 kcal |
| Large wine glass (250 ml) | 13% | 3.3 | 1.8 | 179 kcal |
| Bottle of wine (750 ml) | 13% | 9.8 | 5.5 | 538 kcal |
| Single spirit, UK (25 ml) | 40% | 1.0 | 0.6 | 55 kcal |
| Double spirit, UK (50 ml) | 40% | 2.0 | 1.1 | 110 kcal |
| Shot, US (44 ml / 1.5 oz) | 40% | 1.8 | 1.0 | 98 kcal |
These calorie figures come in under what the label says, and the gap is not an error. A pint of 4% lager might print 180 to 215 kcal on the label because that figure counts residual carbohydrate from the malt on top of the ethanol. Cider, sweet wine, liqueurs, and anything mixed with a sugary soft drink carry the same extra load. For a dry spirit with a zero-calorie mixer, the alcohol figure is close to the whole story. For everything else, read it as the floor.
How long alcohol takes to leave your body
The liver clears roughly one UK unit (8 g of alcohol) an hour, which is where the metabolism estimate on this page comes from. It is a softer number than it looks. Absorption lags, so processing only gets going around 30 minutes after your first drink, and the rate itself barely moves, so drinking faster than about a unit an hour just queues alcohol up in your bloodstream.
Nothing shortens the clock. Coffee, cold showers, food after the fact, a hard workout the next morning: the rate stays where it was. Body size, sex, liver health, medication, and genetics push it up or down by amounts this calculator has no way of knowing, so treat the output as a rough average. It is not a blood alcohol reading. Do not use it to decide whether to drive.
What 75 alcohol-free days actually adds up to
Take a moderate baseline: three drinking sessions a week, two 568 ml pints of 4% lager each time. That is 13.6 units a week, already brushing the UK 14-unit guideline. Run it across a 75-day challenge (about 10.7 weeks) and skipping it entirely saves roughly 146 units, around 8,000 calories from alcohol alone (about 2.3 lb worth of stored fat at 3,500 kcal per pound), and about 146 hours of liver processing time, close to six full days.
Turning that into a habit is the harder part. Reset75 ships No Alcohol as a checkbox task in its Nutrition category, included in the 75 Tough template and available for any custom challenge. You also pick how strict to be: strict mode restarts the attempt if you miss a day, forgiving mode lets you pick the streak back up. Worth deciding which one you want before day one rather than halfway through a bad week.
After that, the sober day counter keeps the streak visible. The money saved not drinking calculator handles the cash side, and the calorie deficit calculator shows how the avoided calories fit a weight goal. Cutting back rather than quitting? The 75 Soft tracker is the forgiving template most people in that position pick.
Frequently Asked Questions
Common questions about alcohol units calculator
How do you calculate alcohol units?
Multiply the ABV by the volume in millilitres, then divide by 1,000. The NHS worked example is a 568 ml pint at 5.2% ABV: 5.2 x 568 / 1,000 = 2.95 units. One UK unit is 10 ml (8 g) of pure alcohol, so a 25 ml shot of 40% spirit is exactly 1 unit.
How many units are in a glass of wine?
At 12% ABV, a 125 ml small glass is 1.5 units, a 175 ml medium glass is 2.1 units, and a 250 ml large glass is 3 units. That large pour alone is over a fifth of the UK weekly guideline of 14 units. A full 750 ml bottle at 13% comes to about 9.8 units.
What counts as one standard drink?
In the US, NIAAA defines a standard drink as 14 g (0.6 fl oz) of pure alcohol: 12 oz of 5% beer, 5 oz of 12% wine, or 1.5 oz of 40% spirits. A UK unit is smaller at 8 g (10 ml). One US standard drink works out to about 1.75 UK units, so the same glass gives you two different numbers depending on where you are.
How many units of alcohol per week is too much?
The UK Chief Medical Officers advise no more than 14 units a week for both men and women, spread over three or more days with several drink-free days. The US no longer publishes a numeric daily limit: the 2025-2030 Dietary Guidelines released in January 2026 replaced it with advice to drink less for better health. CDC still defines heavy drinking as 8 or more drinks a week for women and 15 or more for men.
How long does alcohol stay in your system?
Roughly one UK unit (8 g of alcohol) per hour once your liver gets going, and processing typically starts around 30 minutes after your first drink. That is an average across people, and it shifts with body size, sex, liver health, medication, food, and genetics. Nothing speeds it up. It is also not a blood alcohol reading, so never use it to decide whether you are fit to drive.
How many calories are in alcohol?
Pure ethanol carries 7 kcal per gram, against 4 kcal for carbohydrate and protein and 9 kcal for fat. A 568 ml pint of 4% lager holds about 17.9 g of alcohol, which is roughly 125 kcal from the alcohol alone. The higher figure on the can (often near 200 kcal) adds residual carbohydrate from the malt. See how those calories fit a weight goal with the calorie deficit calculator.
How many units are in a pint of beer?
A 568 ml UK pint is 2 units at 3.6% ABV, 2.3 units at 4%, and 3 units at 5.2%. A US 12 oz can (355 ml) at 5% works out to 1.8 UK units but exactly 1 US standard drink, since the US counts 14 g of alcohol per drink and the UK counts 8 g per unit.
Is this alcohol units calculator private?
Yes. Every calculation runs in your browser, your inputs are saved to localStorage on your own device, and nothing is sent to a server. If you want the same privacy for daily tracking, Reset75 works offline with no account, and No Alcohol is a built-in checkbox task you can add to any challenge.