Standard Drinks Calculator
How many standard drinks — or UK units — are in a glass, bottle or round, from its size and strength.
A standard drink is a fixed amount of pure alcohol, and the amount differs by country: 10 g in Australia, 8 g in the United Kingdom (where it is called a unit), and 14 g in the United States.
How the standard drinks calculator works
A standard drink is a fixed amount of pure alcohol, and the amount differs by country: 10 g in Australia, 8 g in the United Kingdom (where it is called a unit), and 14 g in the United States. So the same glass of wine is 1.4 Australian standard drinks, 1.75 UK units, or 1.0 US standard drinks — the drink has not changed, only the yardstick.
The calculation is volume × ABV × the density of alcohol, 0.789 g/ml, divided by the local definition. The commonest surprize is how far a generous home pour departs from a measured one: a "glass of wine" poured at home is often half as much again as the 150 ml a bar would serve.
Formula: standard drinks = volume (ml) × ABV% ÷ 100 × 0.789 ÷ grams per standard drink
Worked examples
| Inputs | Standard drinks | Note |
|---|---|---|
| A 150 ml glass of 13% wine | 1.54 | 1.54 Australian standard drinks |
| The same glass counted as UK units | 1.95 | 1.95 units — the UK unit is smaller |
| A 330 ml bottle of 4.8% beer | 1.25 | 1.25 Australian standard drinks |
| A 750 ml bottle of 13% wine | 7.69 | 7.7 AU standard drinks — or 9.8 UK units, or 5.5 US drinks |
FAQFrequently asked questions
What is a standard drink?
A fixed amount of pure alcohol — but not the same kind of amount. Australia uses 10 g and the US 14 g, both by weight; the UK unit is 10 ml, by volume. So the same glass counts differently in each country.
How many units in a bottle of wine?
At 13% ABV a 750 ml bottle is 9.8 UK units, 7.7 Australian standard drinks or 5.5 US standard drinks. At 13.5% it is about 10.1 UK units, which is where the familiar "ten units a bottle" comes from. Always quote the ABV — between 12% and 14% the answer moves by nearly two units.
Why does a US drink count for fewer?
Because a US standard drink is 14 g of alcohol against the UK unit's 10 ml, which is about 7.9 g — so one US drink holds roughly 75% more alcohol. Reading a UK guideline against a US or Australian tracker gives a materially wrong answer.
Why compute UK units by volume?
Because that is the legal definition — 10 ml of pure ethanol. Converting to grams and dividing understates UK units by about 1.3%, which is small but wrong.
Does this tell me if I can drive?
No. Blood alcohol depends on body weight, sex, food, time and individual metabolism, and legal limits differ by country and licence. This counts drinks, nothing more.
Where these figures come from
- US FDA — Safe Minimum Internal Temperatures — the internal temperatures the roasting calculator targets
- NIST SP 811 — Guide for the Use of the International System of Units — the exact weight and volume conversions used throughout
- US Food and Drug Administration — food safety and labelling standards
Last checked: September 2026. Baking ratios follow standard baker's percentage practice; roasting guidance follows published safe internal temperatures.