A pint isn’t just a pint

If you cook a lot, you already think in ratios. Salt changes a sauce. Fat changes texture. Alcohol works the same way: volume and strength both matter.

That’s what alcohol units are trying to measure — the amount of pure alcohol in a drink, regardless of whether it’s beer, wine, or whiskey.[2]

In the UK system, one unit equals 10ml (or 8g) of pure alcohol.[2] The quick calculation is:

Units = drink volume (ml) × ABV (%) ÷ 1000.[1][2]

So a 175ml glass of wine at 13% ABV works out to about 2.3 units.[1][2] A pint of 5% beer lands closer to 2.8 units.[1]

Once you start doing the math, restaurant pours suddenly make more sense. That “easy drinking” hazy IPA at 6.8% hits very differently than a crisp 4% lager, even if both arrive in the same chilled pint glass.

ABV changes faster than most people notice

ABV — alcohol by volume — is the percentage of alcohol in the drink.[1][2]

A few percentage points make a bigger difference than people expect:

  • 330ml beer at 4% ABV = roughly 1.3 units[1]
  • 330ml beer at 7% ABV = roughly 2.3 units[1]
  • 250ml wine at 14% ABV = roughly 3.5 units[1][2]

That’s why cocktails can get slippery too. The glass size tells you almost nothing. A short Negroni can carry more alcohol than a full pint of lower-strength beer depending on the pour.

Restaurants and bars have also leaned harder into higher-ABV craft beer, natural wine, barrel finishing, and oversized serves over the last decade. Great for flavor. Easy to underestimate after the second round.

The weekly number adds up like pantry spending

UK guidance advises not to regularly exceed 14 units per week, ideally spread across several days rather than compressed into one night.[3][4] Sources discussing drinking guidance also warn against “saving up” units for weekend binge drinking.[6]

The part that catches people is accumulation.

Two generous glasses of 13% wine with dinner can already put you around 4.5 to 5 units.[1][2] Add a pre-dinner cocktail or a nightcap and suddenly a casual Friday looks very different on paper.

I think unit calculators are useful for the same reason kitchen scales are useful. Not because every meal needs precision, but because your intuition drifts. Especially with stronger pours, larger glasses, and beers that taste softer than their ABV suggests.

And honestly, some drinks deserve the attention. A beautifully bitter amaro, a smoky Scotch, a farmhouse saison with real funk — these are sipping ingredients as much as beverages. Knowing the numbers just helps pace the meal better.

Sources