How to Calculate Alcohol Units and Calories (the Real NHS Method)
A single large glass of wine, 250ml at 12% ABV, is already 3 units, over a fifth of the NHS’s recommended weekly limit in one glass.
The real NHS unit formula
Units = ABV% × volume (ml) ÷ 1000. It’s the same formula for every drink, you just need the strength (printed on the label as % ABV) and the volume in millilitres.
Four common drinks, worked out
- Pint of higher-strength lager, beer or cider (568ml, 5.2% ABV): 568 × 5.2 ÷ 1000 = 2.95 units
- Standard glass of wine (175ml, 12% ABV): 175 × 12 ÷ 1000 = 2.1 units
- Large glass of wine (250ml, 12% ABV): 250 × 12 ÷ 1000 = 3.0 units
- Single shot of spirits (25ml, 40% ABV): 25 × 40 ÷ 1000 = 1.0 unit
Where the calorie figure comes from
The NHS confirms that alcohol itself contains 7 calories per gram. A UK unit is defined as 10ml of pure alcohol, which works out to roughly 8g, so 8 × 7 = around 56kcal per unit from the alcohol alone. A real drink’s total calories are usually higher than this, since most drinks also have sugar or other carbohydrate on top of their alcohol, this figure is the alcohol’s own contribution, not the full drink.
The 14-units-a-week guideline
The NHS advises that both men and women shouldn’t regularly drink more than 14 units a week, spread across three or more days with several drink-free days, not saved up for one session.
Add up your own real total
Our Alcohol Units & Calories Calculator lets you tick off the drinks you’ve actually had, or add a custom drink by its own ABV and volume, and totals your real units and alcohol calories against the 14-unit guideline.
This article is general information, not personalised medical or dietary advice. If you have a specific health condition or concern, speak to a registered dietitian or your GP.