Alcohol Units Calculator
Add up UK alcohol units, national standard drinks, grams of pure ethanol and calories across a week of drinks, with editable national standards.
Standard and units
Drinks in a typical week
Weekly total
18.5 UK units a week
Per drink
| Drink | Serving | ABV | UK units each | Ethanol each | Per week | UK units / week |
|---|---|---|---|---|---|---|
| Pint of beer or cider (568 mL, 4.5%) | 568 mL | 4.5% | 2.56 | 20.2 g | 4 | 10.22 |
| Medium glass of wine (175 mL, 12%) | 175 mL | 12.0% | 2.10 | 16.6 g | 3 | 6.30 |
| UK single spirit measure (25 mL, 40%) | 25 mL | 40.0% | 1.00 | 7.9 g | 2 | 2.00 |
| Week total | 18.52 | 146.2 g | 9 | 18.52 |
A UK unit is 10 mL of pure ethanol, which is 7.9 g at the 0.789 g/mL density of ethanol — so ABV% × volume in mL ÷ 1,000 gives units directly. A 568 mL pint at 4.5% is 2.56 units; a 12 US fl oz beer at 5% works out at 354.9 × 0.05 × 0.789 = 14.0 g, which is exactly one US standard drink by definition.
Estimates only, not medical advice. Units and standard drinks measure the ethanol in a glass, not its effect on you — blood alcohol concentration depends on body water, sex, food, medication and how quickly you drank. Home-poured measures are notoriously larger than the nominal serving, so a real week is usually higher than a calculated one. The calorie figure counts ethanol only, at 7 kcal per gram; residual sugar in wine, cider and mixers adds more. National guidelines differ, are not directly comparable between countries, and are floors for lower risk rather than a safe amount — no level of drinking is risk-free, and the guideline field here is editable precisely because the number depends on where you live. If you are worried about your drinking, talk to a clinician.
What is the Alcohol Units Calculator?
A UK alcohol unit is ABV percentage multiplied by the volume in millilitres, divided by 1,000 — one unit is 10 mL of pure ethanol, or 7.9 grams. Other countries define a standard drink by mass instead: 14 grams in the United States and 10 grams in Australia.
- UK units, national standard drinks, grams of ethanol and calories in one view
- Sixteen built-in servings covering UK, US and Australian pours
- Switchable national standard with an editable grams-per-standard-drink figure
- Editable weekly guideline with a percentage-of-guideline band
- Millilitre or US fluid ounce entry, converted automatically
- Runs fully offline in your browser — nothing you drink is uploaded anywhere
How to use the Alcohol Units Calculator
- 1
Choose your national standard, or set the grams of ethanol per standard drink yourself.
- 2
Pick millilitres or US fluid ounces, and set the weekly guideline you want to be measured against.
- 3
For each row, choose a preset drink or select Custom and enter your own volume and ABV.
- 4
Enter how many of each drink you have in a typical week, adding or removing rows as needed.
- 5
Read the weekly totals in UK units, standard drinks, grams of ethanol and calories, plus the per-drink table.
About the Alcohol Units Calculator
The ByteTools Alcohol Units Calculator adds up a typical week of drinks and reports it four ways: UK units, standard drinks under whichever national definition you select, grams of pure ethanol, and calories from that ethanol. Sixteen common servings are built in, from a UK pint and a 175 mL glass of wine to a US 12 fl oz beer and a 44 mL shot, and any row can be switched to a custom volume and ABV.
Because national standards differ by mass — 10 g in Australia, 14 g in the United States, 7.9 g for a UK unit — the same list of drinks produces different totals depending on where you live. The grams-per-standard-drink figure and the weekly guideline are both editable fields, so the tool can report the right number for your country rather than assuming one.
Everything is calculated in your browser and nothing you enter is uploaded or stored. These are estimates only and not medical advice: units measure the ethanol in the glass, not its effect on you, and home-poured measures are almost always larger than the nominal serving.
Frequently asked questions
How do you calculate alcohol units?
Multiply the ABV percentage by the volume in millilitres and divide by 1,000. A 568 mL pint at 4.5% is 2.56 units, and a 175 mL glass of 12% wine is 2.1 units. One UK unit is 10 mL of pure ethanol, which weighs 7.9 grams.
How many units are in a bottle of wine?
A 750 mL bottle at 13.5% ABV contains 10.1 units, so a standard bottle is around ten units. That is most of the way to the UK's 14-unit weekly low-risk guideline from a single bottle, which surprises a lot of people.
Is a UK unit the same as a US standard drink?
No. A UK unit is 10 mL of ethanol, about 7.9 grams, while a US standard drink is 14 grams — roughly 1.8 UK units. Australia uses 10 grams. Weekly guidelines from different countries are therefore not directly comparable, which is why the standard here is switchable.
How many calories are in alcohol?
Ethanol carries 7 kcal per gram, so a UK unit contributes about 55 kcal before anything else in the drink is counted. This calculator totals the ethanol calories only; residual sugar in wine, cider, liqueurs and mixers adds more on top.
What is the weekly alcohol guideline?
UK guidance is no more than 14 units a week for everyone, spread over three or more days. Other countries set different limits and some differ by sex. Guidelines describe lower risk rather than no risk, which is why the figure here is a field you set yourself.
Why is my real intake usually higher than I calculate?
Because home measures run large, restaurant wine glasses are often 250 mL rather than 175 mL, and craft beers frequently sit at 6% or more rather than the 4% many people assume. Entering the actual ABV from the label and the actual pour size closes most of the gap.
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