Standard drinks calculator

How to use it

1. Enter the volume. In mL or US fluid ounces - a whole bottle, or a single glass. Tap a tick for common bottle sizes.
2. Enter the strength. The % ABV on the label, or US proof.
3. Set a serving. Optional: 25 mL is a UK single measure, 1½ fl oz (44 mL) a US shot; a glass of wine is about 150 mL.

How it works

The volume times the strength gives the volume of pure alcohol, and alcohol weighs 0.789 g per mL. A standard drink is a fixed amount of that alcohol, but the amount is set country by country: a UK unit is 10 mL (8 g), a US standard drink 14 g, a Canadian one 13.45 g, and 10 g in Australia, New Zealand, Ireland, France and Japan. The calculator shows them all.

A worked example

A 750 mL bottle at 40% holds 300 mL - 237 g - of alcohol: 29.6 UK units, or 16.9 US standard drinks. That's 30 single 25 mL measures of one unit each, or nearly 17 US shots of 1½ fl oz.

A 700 mL bottle at the same strength holds 28 units.

Questions

How many units are in a bottle of spirits?

A 700 mL bottle at 40% holds 28 UK units; a 750 mL bottle about 30.

How many standard drinks are in a shot?

A US shot of 1½ fl oz at 40% is one US standard drink. A 25 mL UK measure at 40% is one UK unit.

Why are standard drinks different in different countries?

Each country sets its own, from about 8 g of alcohol in the UK to 14 g in the USA, so the same glass counts as a different number of drinks.

What are the UK drinking guidelines?

The UK Chief Medical Officers advise no more than 14 units a week, spread over three or more days, with some days without alcohol.

Does home-distilled spirit count the same?

Yes - alcohol is alcohol. Measure the strength accurately (corrected for temperature) and the calculator does the rest.