Alcohol Units & Standard Drinks Calculator
Count the UK alcohol units and US standard drinks in any mix of drinks from the size and ABV, and compare a week, a day or one occasion with NHS and CDC guidance.
How to Use
- Add each drink: choose a type and the size and strength fill in, or enter your own size (mL or fl oz) and the ABV from the label.
- Set how many of each you had.
- Choose whether the list is for a week, a typical day or one occasion, so the right guideline is used.
- Pick sex for the US comparisons (the CDC uses different numbers for men and women; the NHS 14 units applies to both).
- Read the UK units, US standard drinks and grams of alcohol, and check Show Work for each drink.
Worked Example
A pint of 5% beer. UK units = 5 × 568 ÷ 1,000 = 2.84 units. The pint holds 28.4 mL of pure alcohol, and 28.4 × 0.789 = 22.4 g, so it is 22.4 ÷ 14 = 1.6 US standard drinks.
A week of wine. Ten 125 mL glasses of 11% wine are 10 × 11 × 125 ÷ 1,000 = 13.75 units, 98% of the NHS guideline of 14 units a week, which the NHS advises spreading over 3 or more days. In US terms it is 108.5 g of alcohol, 7.75 standard drinks.
The common mistake: counting glasses as units. A 175 mL glass of 12% wine is not one unit but 12 × 175 ÷ 1,000 = 2.1 units, and a whole 750 mL bottle at 13.5% is 10.1 units, not the 4 or 5 “glasses” it pours. Counted by the glass, six glasses a week looks like 6 units; it is really 12.6.
Show Work
Formulas
Units, Standard Drinks and the Guidelines
Counting alcohol in units began in the UK in 1987, as a simple way to keep track of drinking. The NHS defines a unit as 10 mL or 8 g of pure alcohol and advises men and women alike not to drink more than 14 units a week on a regular basis, spread over three or more days. Its table of common drinks runs from 1 unit for a 25 mL single spirit to 3 units for a pint of 5.2% lager or a large glass of wine.
The United States counts in standard drinks instead. The National Institute on Alcohol Abuse and Alcoholism defines one as 14 g, about 0.6 fl oz, of pure alcohol, and points out that a 12 fl oz craft beer at 10% is two of them. The CDC uses standard drinks to describe moderate, heavy and binge drinking. The Dietary Guidelines for Americans 2025–2030 put it briefly: consume less alcohol for better overall health, and some people, including pregnant women and people recovering from alcohol use disorder, should avoid it completely.
About This Tool
This calculator adds up any mix of UK and US drinks, in millilitres or fluid ounces, and gives the total in UK units, US standard drinks and grams of pure alcohol. It compares a week with the NHS 14-unit guideline and the CDC heavy-drinking level, a typical day with the CDC description of moderate drinking (and the NHS weekly figure if every day were the same), and one occasion with the CDC binge level, drawing each against its line. Sources: NHS “Alcohol units” (reviewed August 2024), NIAAA “What Is a Standard Drink?”, CDC “Alcohol Use and Your Health” (January 2025) and the Dietary Guidelines for Americans 2025–2030.
The guidelines are the agencies’ own wording; this tool only measures your drinks against them. Everything runs in your browser; nothing you enter is sent anywhere.
For general information only — not medical advice. Talk to a doctor or other qualified professional about your own health.
Related tools: BAC Calculator, Caffeine Intake & Half-Life Calculator, and Blood Pressure Category Checker.
Frequently Asked Questions
What is one unit of alcohol?
In the UK one unit is 10 mL, or 8 g, of pure alcohol, which the NHS describes as around the amount the average adult can process in an hour. Units = ABV (%) × volume (mL) ÷ 1,000, so a 568 mL pint of 5.2% lager is 5.2 × 568 ÷ 1,000 = 2.95 units.
How many units are in a bottle of wine?
A 750 mL bottle at 13.5% is 13.5 × 750 ÷ 1,000 = 10.1 units (the NHS rounds it to 10). At 12% it is 9 units. A 175 mL standard glass of 12% wine is 2.1 units and a 250 mL large glass is 3 units.
How does a US standard drink compare with a UK unit?
A US standard drink is 14 g of pure alcohol (NIAAA): a 12 fl oz beer at 5%, a 5 fl oz glass of wine at 12% or a 1.5 fl oz shot of 40% spirits. A UK unit is 10 mL, about 7.9 g, so one US standard drink is 1.77 UK units and one unit is 0.56 of a US drink.
What is the NHS weekly limit?
The NHS advises men and women not to drink more than 14 units a week on a regular basis, and to spread it over 3 or more days if you drink that much. It says 14 units is about 6 pints of average-strength beer or 10 small glasses of lower-strength wine. Six pints of 4% beer is 13.6 units.
What do US guidelines say?
The Dietary Guidelines for Americans 2025–2030 say to consume less alcohol for better overall health, and that some people should avoid it completely, including pregnant women. The CDC describes moderate drinking as 2 drinks or less a day for men and 1 or less for women, heavy drinking as 15 or more drinks a week for men and 8 or more for women, and binge drinking as 5 or more drinks on one occasion for men and 4 or more for women.
How do I use the Alcohol Units & Standard Drinks Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Is it free? Does it work without internet?
Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.
Where does my data go?
Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.
Common Use Cases
Keeping a weekly count
Six pints of 4% beer in a week is 13.6 units, just under the NHS 14; a seventh pint takes it to 15.9.
Comparing glass sizes
Wine at 12% is 1.5 units in a 125 mL glass, 2.1 in a 175 mL glass and 3 in a 250 mL glass.
Reading a US label
A 12 fl oz can at 5% holds exactly one US standard drink (14 g) and 1.77 UK units.
A night out
Five 25 mL single spirits and two pints of 5% beer add up to 10.7 units, or 6 US standard drinks, past the CDC binge level of 4 for a woman.
A daily habit
Three 12 fl oz beers every day is 3 US drinks a day and 37.3 UK units a week, more than 2.6 times the NHS weekly guideline.
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