Alcohol Unit Calculator (UK)
Estimate how many alcohol units are in your drink and your weekly total. Formula used: Units = (Volume in ml × ABV%) ÷ 1000.
What is an alcohol unit?
An alcohol unit is a way to measure pure alcohol content in a drink. In the UK, 1 unit = 10 ml (or 8 g) of pure alcohol. Because drinks come in many sizes and strengths, units help you compare them accurately.
For example, a large glass of strong wine can contain far more alcohol than a small beer. Tracking units gives you a clearer picture of your intake than “number of drinks” alone.
How alcohol units are calculated
The calculator uses this standard formula:
Alcohol units = (Volume in ml × ABV %) ÷ 1000
- Volume is the total liquid amount in milliliters.
- ABV is alcohol by volume, printed as a percentage.
- Divide by 1000 to convert to UK units.
Example
If you drink a 500 ml beer at 5% ABV:
(500 × 5) ÷ 1000 = 2.5 units
Typical drinks and approximate units
| Drink | Typical Size | ABV | Approx. Units |
|---|---|---|---|
| Beer (pint) | 568 ml | 4.0% | 2.27 |
| Lager can | 440 ml | 4.0% | 1.76 |
| Wine (small glass) | 125 ml | 12% | 1.50 |
| Wine (large glass) | 250 ml | 12% | 3.00 |
| Spirits (single shot) | 25 ml | 40% | 1.00 |
| Bottle of wine | 750 ml | 13% | 9.75 |
Why track your weekly units?
Keeping a weekly view helps you spot patterns and reduce risk. UK low-risk guidance is often summarized as no more than 14 units per week, spread over several days, with drink-free days built in.
Tips to reduce alcohol intake
- Choose lower-ABV beers, wines, or no/low-alcohol alternatives.
- Alternate alcoholic drinks with water or soft drinks.
- Use smaller glasses at home to naturally reduce volume.
- Set a weekly unit target before social events.
- Track drinks in real time rather than estimating later.
Frequently asked questions
Are units the same in every country?
No. This page uses the UK definition of a unit. Other countries use different standard drink systems.
Does a stronger craft beer change the result a lot?
Yes. ABV has a big impact. A 330 ml beer at 8% ABV contains nearly double the units of a 330 ml beer at 4.2% ABV.
Can this calculator help with calorie tracking?
Not directly. Alcohol units measure pure alcohol amount, not calories, but higher-unit drinks often carry higher calorie loads too.