Guide · numbers
One unit is 10 grams of pure alcohol
The unit is the measure that makes drinks comparable: a shot of vodka, a glass of wine and half a litre of beer turn out to be surprisingly close. Work it through once and the question «which is stronger» answers itself.
Common servings
Units rounded to one decimal place.
- Vodka 40 ml · 40% vol
- 1.3 units · ~90 kcal
- Whisky 40 ml · 40% vol
- 1.3 units · ~90 kcal
- Wine 150 ml · 13% vol
- 1.5 units · ~125 kcal
- Sparkling 150 ml · 12% vol
- 1.4 units · ~120 kcal
- Beer 500 ml · 5% vol
- 2.0 units · ~210 kcal
- Cider 500 ml · 4.5% vol
- 1.8 units · ~230 kcal
Calories are approximate: pure alcohol gives 7 kcal per gram and the rest comes from sugar. A sweet cider or liqueur carries more calories at the same strength.
How to calculate it yourself
The formula is simple: ml × %vol × 0.789 ÷ 1000 ÷ 10 = units. The 0.789 is the density of alcohol; dividing by ten comes from the unit being 10 grams.
In practice a shortcut is enough: ml × %vol ÷ 1270 gives the same answer to one decimal. For example 500 × 5 ÷ 1270 = 1.97, so two units in half a litre of 5% beer.
The Estonian National Institute for Health Development (TAI) puts the low-risk boundary at up to 4 units a day and 21 a week for men, up to 2 a day and 14 a week for women, plus at least three alcohol-free days a week. These are figures about risk, not permission.
Where the calories come from
7 kcal per gram — more than sugar, less than fat. This part cannot be avoided.
Liqueur, sweet cider, sweet sparkling. This is where the biggest difference appears at equal strength.
Cola, juice and syrup often add more than the alcohol does.
Dry wine and dry sparkling are tens of calories lighter at the same strength.
Calories come from carbohydrates as well as alcohol — which is why a strong beer is a serious number.
Common questions
What does one unit look like in practice?
10 g of pure alcohol: roughly 30 ml of a 40% spirit, 100 ml of wine or 250 ml of 5% beer.
Do stronger drinks carry more calories?
From the alcohol, yes — but a sweet weaker drink can total more. Alcohol plus sugar decides it.
Is a unit the same everywhere?
No. Estonia and most of Europe use 10 g, the UK 8 g, the USA 14 g. Always compare with the same measure.
Is beer «lighter» than wine?
Per serving, usually not: half a litre of 5% beer gives more units than a glass of wine.