How does my drinking add up

Self-reported alcohol consumption data show that 24% of adults in Scotland in 2018 exceeded the low-risk weekly drinking guideline for both men and women.

With so many different drinks and glass sizes, from shots to pints – not to mention bottles – it's easy to get confused about units and how much you are drinking.

An easy mistake is to think one drink equals one unit. It doesn't.

Units explained

Units are a way to describe the quantity of pure alcohol in a drink. This was developed to help people understand how much alcohol they are drinking, because it is the alcohol itself that is harming people’s health.

The number of units in a drink can vary depending on the bottle or glass size, as well as the strength of the alcohol.


Alcohol strength at a glance
Alcohol units at a glance NHS Health Scotland

Calculating units

The number of units in a drink can be calculated from the alcohol by volume (ABV) and the size of the drink.

The higher the ABV, the stronger the drink.

You can find the ABV on the labels of alcoholic drinks where it's sometimes written as "vol" or "alcohol volume" with

the number of units in a bottle often illustrated on the back.

Bar staff can explain alcohol content too.

For example, wine that says "12% ABV" or "alcohol volume 12%" means 12% of the volume of that drink is pure alcohol.

Doing the sum

You can work out how many units there are in any drink by multiplying the total volume of a drink (in ml) by its ABV (measured as a percentage) and dividing the result by 1,000.

  • strength (ABV) x volume (ml) ÷ 1,000 = units

So, to work out the number of units in a pint (568ml) of strong lager (ABV 5.2%):

  • 5.2 (%) x 568 (ml) ÷ 1,000 = 2.95 units

Based on the sample range of drinks above, fourteen units is equivalent to 6 pints of beer, 6 glasses of wine or 7 double measures of spirits.

Still not sure about units? Try the Scottish Government's alcohol unit generator and alcohol unit calculator.

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