Alcohol Content Calculator (mL × ABV → grams)

Understanding the alcohol content calculator — concept and principle

Labels show a drink's strength as a percentage, alcohol by volume (ABV), but health guidelines count alcohol in grams or in "standard drinks" and "units". This calculator converts a drink's volume and ABV into millilitres and grams of pure ethanol, then expresses the result as UK units, US standard drinks and 10-gram standard drinks used in Australia and many other countries. It helps you compare a beer with a glass of wine or a bottle of soju on one scale.

How it is calculated

• Ethanol (mL) = volume (mL) × ABV ÷ 100 × number of drinks
• Ethanol (g) = ethanol (mL) × 0.789, the density of ethanol in g/mL
• UK units = ethanol (mL) ÷ 10 (one unit is 10 mL, about 8 g)
• US standard drinks = grams ÷ 14
• 10 g standard drinks = grams ÷ 10

Results are rounded to one decimal place.

The principle

ABV states what share of the liquid's volume is pure ethanol, so multiplying volume by ABV gives the ethanol volume. The body, however, processes alcohol by mass, and guidelines are written in grams, so the volume is multiplied by ethanol's density, 0.789 g/mL at room temperature. Different countries then chose different round amounts as their reference "drink": the US uses 14 g (about 0.6 fl oz of pure alcohol), the UK counts units of 10 mL, and countries such as Australia use 10 g.

Worked example

1. Ethanol volume = 500 × 5 ÷ 100 × 1 = 25 mL.
2. Mass = 25 × 0.789 = 19.725, shown as 19.7 g.
3. UK units = 25 ÷ 10 = 2.5.
4. US standard drinks = 19.725 ÷ 14 = 1.41, shown as 1.4.
5. 10 g standard drinks = 19.725 ÷ 10 = 1.97, shown as 2.

How to read the result

The gram figure is the most comparable number across countries. For reference, a 360 mL bottle of 16% soju contains about 45.4 g, more than two 500 mL cans of 5% beer. Official low-risk guidance differs: the UK Chief Medical Officers advise not regularly drinking more than 14 units a week, and many health authorities stress that no level of drinking is entirely risk-free.

Common mistakes

• Counting "one drink" as one glass regardless of size or strength.
• Confusing US proof with ABV (US proof is twice the ABV).
• Mixing up UK units (10 mL) with US standard drinks (14 g).
• Forgetting to set the number of drinks above 1 for multiple servings.

Frequently asked questions

How many grams of alcohol are in a 500 mL beer at 5%?

About 19.7 g, which is roughly 1.4 US standard drinks or 2.5 UK units.

Why multiply by 0.789?

Ethanol is lighter than water; one millilitre of pure ethanol weighs about 0.789 g.

Is a UK unit the same as a standard drink?

No. A UK unit is 10 mL (about 8 g) of ethanol, smaller than the 14 g US standard drink.

Sources: NIAAA, What Is A Standard Drink? · UK Chief Medical Officers' Low Risk Drinking Guidelines (2016)