Alcohol units calculator
How much pure alcohol and how many standard units a serving holds.
Fill in the fields and the result will appear here automatically.
Converts drink volume and ABV into millilitres and grams of ethanol, then divides the mass by the selected grams per standard unit. It compares stated drink quantities under one unit definition. Definitions vary: a US standard drink contains about 14 g, whereas a UK unit is 10 mL, approximately 8 g. The retained 10 g field value is a chosen illustration, not the UK definition or a universal safe serving.
How it works
Formula and logic
Ethanol mL = drink mL × ABV/100; grams = ethanol mL × 0.789 g/mL; units = grams ÷ selected grams per unit. Density is a fixed approximation. Drink volume and unit mass must be positive; ABV may range from 0 to 100%. The UK volume calculation using 10 mL does not exactly equal the approximation using 8 g.
Example
150 mL at 12% ABV contains 18 mL or 14.202 g of ethanol: a 10 g unit gives 1.42 units. At 0% ABV the result is zero. An 8 g unit gives 1.78 by this mass model; the UK volume formula gives 1.8.
Fields and units
- Serving volume, ml — mL
- Strength, % ABV — unitless
- Unit definition, g of alcohol — g
How to use
- — Enter the drink’s actual volume in millilitres and its ABV percentage.
- — Choose grams per unit for your intended definition; page language does not select a country.
- — For several drinks, calculate each and add results using the same unit definition.
- — Drink volume, ethanol volume and ethanol mass are different quantities.
Method and limitations
- Calculation method
- Formula and logic
- Data or methodology source
- NHS: a UK unit is 10 mL or about 8 g alcohol; its volume formula differs from this model’s selected density NIAAA: a US standard drink contains about 14 g alcohol; not an intoxication measure or driving permission
- Limitation
- Ethanol quantity is not an assessment of intoxication, blood alcohol, elimination time or fitness to drive, and supplies no medical consumption recommendation.
FAQ
Why enter the unit definition myself?
Definitions are conventions: the US uses about 14 g, while a UK unit is 10 mL or approximately 8 g. This tool divides ethanol mass; its initial 10 g value does not assert an international standard.
Does this show intoxication?
No. Time, body weight and other factors needed for estimating blood alcohol are absent. The unit count neither permits driving nor defines a safe amount to consume.
Why do mass and volume of alcohol differ?
Volume is measured in millilitres, mass in grams. The model relates them using the chosen approximate density of 0.789 g/mL; their numerical values need not be equal.
How do I count a whole evening?
Calculate each drink with the same grams-per-unit value, then add units or grams. The sum records ethanol quantity without estimating elimination.