Standard Drink Calculator — How Many Standard Drinks?
Enter the volume and alcohol percentage of a drink to find how many standard drinks it contains under Australian/NZ (10 g), UK (8 g), or US (14 g) definitions, and see how it compares to low-risk daily guidelines.
mL
%
Standard drink definition
Pure ethanol content divided by grams per standard drink
- 1
Pure ethanol volume
330 mL × 5% ÷ 100 = 16.5 mL - 2
Pure ethanol weight
16.5 mL × 0.789 g/mL = 13.02 gEthanol density at room temperature is 0.789 g/mL. - 3
Standard drinks
13.02 g ÷ 10 g/drink = 1.30
How does this calculator work?
Standard drinks = (volume mL × ABV% ÷ 100 × 0.789) ÷ grams per standard drink. A 330 mL beer at 5% ABV contains roughly 13 g of pure alcohol — 1.3 Australian standard drinks, 1.6 UK units, or 0.93 US standard drinks. Daily guidelines are 2–3 standard drinks depending on jurisdiction.
Formula
How this is calculated
Ethanol (drinking alcohol) has a density of approximately 0.789 g/mL at room temperature. Multiplying the drink volume by the alcohol-by-volume percentage gives the volume of pure ethanol in the glass; multiplying by the density converts that to grams.
A "standard drink" is a government-defined unit of pure alcohol that makes it easier to track consumption without thinking about individual beverages. The gram threshold differs by country: Australia and New Zealand use 10 g, the UK defines one unit as 8 g, and the US standard drink equals 14 g. Dividing the pure alcohol content by the relevant threshold gives the number of standard drinks.
Health agencies generally recommend no more than 2–3 standard drinks per day (and no more than 10–14 per week) for low-risk drinking. This calculator uses those reference numbers only as a contextual benchmark — they are guidelines, not medical advice, and do not account for individual factors such as body weight, medications or medical conditions.
Frequently asked questions
Each country sets its own public-health messaging and alcohol labelling independently. Australia chose 10 g in 1987, the UK has used 8 g since the 1980s, and the US has used 14 g since the 1990s. All are based on research into the metabolism rate and risk thresholds specific to those countries.
Labels are accurate to ±0.5% by law in most countries, so the result is a close estimate rather than a precise figure. Home-brewed or unlabelled drinks may vary more widely.
The calculator shows the health-authority guideline for that country: 2 drinks/day for Australia and the US, 3 units/day for the UK. These are population-level advisory figures — actual risk depends on individual health, age, medications and drinking pattern.
Also known as
TG we-Calculate Editorial Team. (2026). Standard Drink Calculator — How Many Standard Drinks? [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/standard-drink-calculator
TG we-Calculate Editorial Team. "Standard Drink Calculator — How Many Standard Drinks?." TG we-Calculate. 2026. https://we-calculate.com/calculator/standard-drink-calculator.
TG we-Calculate Editorial Team, "Standard Drink Calculator — How Many Standard Drinks?," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/standard-drink-calculator
@misc{wecalculate_standard_drink_calculator, title = {Standard Drink Calculator — How Many Standard Drinks?}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/standard-drink-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?