How the numbers are worked out
First the drink's pure alcohol: millilitres times ABV gives the millilitres of ethanol, and ethanol weighs 0.789 g per millilitre. A 500 ml beer at 5% holds 25 ml of ethanol, which is 19.7 g. That figure is then divided by each country's standard drink.
The UK is the exception, because the NHS defines a unit by volume, 10 ml of pure alcohol. So UK units are simply millilitres times ABV divided by 1000, which is the formula the NHS calculator uses. Counted by weight instead, 8 g is slightly more than 10 ml (7.9 g), and a pint would come out a little lower.
The drink sizes in the list are typical pours, not rules. Bars pour differently, wines run from 11% to 15%, and craft beer often sits well above 5%. Use the volume and ABV printed on what you're actually drinking whenever you can.
Why countries disagree
There's no international standard. A 2016 survey of 37 countries by Kalinowski and Humphreys found official definitions from 8 g to 20 g, with 10 g the most common. The WHO uses about 10 g as a guide value, but that's a reference point rather than a binding definition. Germany and Switzerland give a range of 10 to 12 g rather than one number, so the calculator shows a range for them too. Some countries have no single official figure at all; Norway and Japan are two, and they're left out of the table rather than given a number.
Austria's Standardglas, about 20 g, is the largest. It's the reference used in the Austrian government's alcohol handbook, which equates it with half a litre of beer or a quarter litre of wine.
Compare advice in grams
Drinking guidance is usually written in the local unit, which makes it easy to compare the wrong things. The NHS advises not regularly drinking more than 14 units a week, which is 112 g of pure alcohol. Fourteen US standard drinks would be 196 g, and fourteen Austrian Standardgläser about 280 g. Convert to grams first, then compare.
What a standard drink doesn't tell you
A standard drink measures what's in the glass, not what it does to you. The same 20 g raises blood alcohol more in a smaller body, more on an empty stomach, and more when it goes down quickly. If that's the question you're asking, the BAC calculator with food draws the estimated curve for a whole evening.
Questions
How many units are in a pint of beer?
A UK pint is 568 ml. At 4% ABV it holds 2.3 UK units, at 5% it holds 2.8. The UK counts a unit as 10 ml of pure alcohol, so units are millilitres times ABV divided by 1000.
How many standard drinks are in a bottle of wine?
A 750 ml bottle at 13% holds about 77 g of pure alcohol. That's 9.8 UK units, 7.7 Australian standard drinks, 5.5 US standard drinks and 3.8 Austrian Standardgläser. Same bottle, four answers.
How many grams of alcohol is a standard drink?
It depends on the country. It's 8 g in the UK (a unit), 10 g in Australia, France, Ireland, the Netherlands, New Zealand, Poland and Spain, 12 g in Denmark, Finland, Italy and Sweden, 13.45 g in Canada, 14 g in the US and about 20 g in Austria. Germany and Switzerland give a range of 10 to 12 g.
Is a UK unit the same as a standard drink?
No. A UK unit is 10 ml or 8 g of pure alcohol, smaller than the 10 g most countries use and a lot smaller than the US standard drink of 14 g. A US standard drink is about 1.75 UK units.
Does a standard drink tell me how drunk I will get?
No. It measures the alcohol in the glass, not what it does to you. The same 20 g raises blood alcohol more in a smaller body, more on an empty stomach and more when it's drunk fast. The BAC calculator on this site shows that curve as an estimate.
Is anything I enter saved or sent?
No. The calculation runs in your browser, and nothing you enter leaves the page.
Sources
Every country's figure links to the health authority that publishes it, in the table's Source column. Also used:
- Kalinowski, A., Humphreys, K. (2016). Governmental standard drink definitions and low-risk alcohol consumption guidelines in 37 countries. Addiction 111:1293-1298.
- Babor, T.F. et al. (2001). AUDIT: The Alcohol Use Disorders Identification Test, 2nd edition. World Health Organization.