Counting drinks by “glasses” gives a different measure for every drink. The NHS counts in units instead — one unit is 10ml, or 8g, of pure alcohol, and men and women are advised not to drink more than 14 units a week on a regular basis. Knowing the strength and the volume lets you measure any drink on the same scale. This sets out the NHS page “Calculating alcohol units”.
1. 1 unit = 10ml (8g) of pure alcohol. The sum is strength (%) × volume (ml) ÷ 1,000.
2. No more than 14 units a week. The same for men and women; if you regularly drink as much as 14, spread it over 3 or more days.
3. A unit is roughly an hour. About what an average adult can process in an hour, though it varies from person to person.
The sum — strength × volume ÷ 1,000
The NHS formula is strength (ABV, %) × volume (ml) ÷ 1,000 = units. A 25ml shot of 40% spirits is 40 × 25 ÷ 1,000 = 1 unit.
The NHS table — units in a drink
| Drink (NHS examples) | Volume · strength | Units |
|---|---|---|
| Single small shot of spirits | 25ml · 40% | 1 |
| Small glass of wine | 125ml · 12% | 1.5 |
| Standard glass of wine | 175ml · 12% | 2.1 |
| Large glass of wine | 250ml · 12% | 3 |
| Bottle of wine | 750ml · 13.5% | 10 |
| Pint of lower-strength lager, beer or cider | Pint · 3.6% | 2 |
| Pint of higher-strength lager, beer or cider | Pint · 5.2% | 3 |
Values are from the NHS page. The page does not give a pint in ml, so none is given here.
Common Korean drinks — our examples
| Example (strength assumed) | Sum | Units |
|---|---|---|
| Bottle of soju, 360ml at 16% | 16 × 360 ÷ 1,000 | About 5.8 |
| Can of beer, 500ml at 5% | 5 × 500 ÷ 1,000 | 2.5 |
| 14 units a week is | 14 ÷ 5.76 · 14 ÷ 2.5 | About 2.4 bottles of soju · 5.6 cans of beer |
The strengths are assumptions to show the sum — use the strength printed on the bottle. 14 units in grams is 14 × 8 = 112g (our arithmetic). Taking the NHS “about an hour per unit” at face value, a bottle of soju is about 6 hours’ worth, but the NHS adds that this varies between people.
How to read 14 units
- The same for men and women. The page gives 14 units to both.
- A limit for regular drinking — if you regularly drink as much as 14 units a week, spread it over 3 or more days.
To read it alongside check-up results such as liver numbers, see health check-up results.
Checklist
- ☐ Check the strength and volume — % × ml ÷ 1,000
- ☐ Does the week’s total pass 14 units?
- ☐ Near 14? Spread it over 3 or more days
- ☐ Before driving the next day, remember it takes time — roughly an hour a unit, varying by person
Questions that remain
Does Korea use the same guideline?
Only the NHS page was read for this article. Korean agencies’ drinking guidelines were not checked in the original and are not given.
What about driving the next day?
Legal blood alcohol limits and penalties are outside this page. Since the NHS says “an hour per unit” is approximate and varies, do not use this sum to decide you are fit to drive (our view).
What people commonly hear about cancer risk and how big the shares really are is in common myths about cancer.
Alcohol is also listed as a heartburn trigger — the NHS says to avoid too much and not eat within 3 or 4 hours of bed (heartburn and acid reflux).
Sources
- NHS — Calculating alcohol units — original (page shows: last reviewed 27 August 2024, next review due 27 August 2027; checked 12 October 2026). 1 unit 10ml or 8g, the formula, 14 units a week over 3 or more days, a unit an hour, the table of drinks.
- Not read. Korean agencies’ drinking guidelines; laws on blood alcohol and driving.
- Our arithmetic. Soju and beer examples (strengths assumed), 14 units as soju and beer, 112g, about 6 hours for a bottle of soju.
Where to check further
- The strength on the bottle — the value for the sum.
- A local clinic if you are worried about drinking.
Written 12 October 2026. The content sets out the NHS original; Korean drink examples and arithmetic are ours. It does not replace diagnosis or treatment.