Standard drink sizes

What counts as one drink

A "drink" is not a fixed amount anywhere in the world. The United States defines a standard drink as 14 g of pure alcohol. The UK uses units of 8 g, Japan counts 20 g, and most of continental Europe works in 10 or 12 g. The same glass of wine can therefore be one drink, one and a half units or two thirds of a unit depending on which country's leaflet you read.

Grams of pure alcohol is the only figure that travels. It comes straight from the glass: millilitres × % vol × 0.789. A pint of 4.5 % beer holds 20 g. A 4 cl shot of 40 % spirit holds 12.6 g. A 0.5 l beer at 5 % holds 19.7 g — more than a US standard drink, which surprises most people.

Why glass sizes matter more than the drink type

There is nothing special about beer, wine or spirits as far as your blood is concerned: the alcohol is the same molecule and the only question is how many grams arrived. What changes between countries is the glass. A German Pils is 0.33 l, a Norwegian halvliter is 0.5 l, a French demi is 0.25 l, an Italian birra piccola is 0.2 l and a Spanish caña is smaller still. Order "a beer" in four countries and you have drunk four different amounts.

The sizes in the table below are the ones served in the market each language of this site is written for, which is also why the quick buttons on the calculator differ per language.

Strength has drifted upwards

Average wine strength has risen by one to two percentage points over a few decades, and craft beer routinely runs at 6 to 8 % where the old default was 4.7. A glass poured today can hold half again as much alcohol as the same glass twenty years ago. If you are estimating a session from memory, check the label rather than the habit — the Another drink box on the calculator takes any size and strength.