What does “standard drink” mean?
A standard drink is a public-health reference amount of pure alcohol. It lets people compare beer, wine, spirits, and mixed drinks that may look very different but contain a similar amount of alcohol.
It is not the same as a serving. A large, strong beer can contain several standard drinks; a small, lower-ABV drink can contain less than one.
Standard drink definitions by country
| Country / term | Pure alcohol reference | Example reference |
|---|---|---|
| United States | 14 g (0.6 fl oz) | 12 fl oz beer at 5%, 5 fl oz wine at 12%, or 1.5 fl oz spirits at 40% |
| Australia | 10 g | Check labels: a standard drink is always 10 g of pure alcohol |
| United Kingdom / unit | 8 g (10 ml) | Units are calculated from the drink’s volume and ABV |
| Canada | 13.45 g (17.05 ml) | 341 ml beer/cider at 5%, 142 ml wine at 12%, or 43 ml spirits at 40% |
| New Zealand | 10 g | One standard drink always contains 10 g of pure alcohol |
| Ireland | 10 g | A standard drink is about a half pint of beer, small glass of wine, or single measure of spirits |
These reference definitions are measurement tools, not a recommendation to drink. Health guidance and product labels can change, so consult your local public-health authority for current guidance.
Why ABV matters
ABV is the percentage of a beverage that is alcohol by volume. Two 12-ounce beers can contain very different amounts of alcohol if one is 4% ABV and the other is 8% ABV. The container size alone cannot tell you the number of standard drinks.
How to calculate it
Estimate pure alcohol in grams with: serving size in ml × ABV as a decimal × 0.789. Then divide by your country’s reference amount. Our calculator does this arithmetic and clearly shows the country-specific unit.
Use the standard-drink calculator
Important limits
Standard drinks do not measure BAC, impairment, tolerance, safety to drive, or the health effect for a particular person. If you have been drinking, do not use any online estimate to decide whether to drive or operate machinery.