UK Alcohol Units Calculator
Estimate units for one drink, a session, and your weekly total using UK guidance.
Formula used: Units = (Volume in ml × ABV%) ÷ 1000.
What is an alcohol unit in the UK?
In the UK, one alcohol unit equals 10ml (or 8g) of pure alcohol. Because drinks come in different sizes and strengths, counting drinks alone can be misleading. A single pint of strong beer may contain more units than several smaller low-strength drinks.
Using a calculator helps you estimate your intake more accurately so you can compare it with UK low-risk drinking guidance.
How this UK units calculator works
The formula
The standard UK formula is:
Alcohol units = (Drink volume in ml × ABV %) ÷ 1000
- Volume is the liquid amount in millilitres (ml).
- ABV is alcohol by volume, shown on the label (for example, 4% or 13%).
- You can multiply by number of servings to get a session total.
Example calculation
For a 175ml glass of wine at 13% ABV:
(175 × 13) ÷ 1000 = 2.275 units, usually rounded to 2.3 units.
Common drink unit estimates
| Drink | Typical Size | ABV | Approx Units |
|---|---|---|---|
| Pint of beer | 568ml | 4% | 2.3 |
| Can of lager | 330ml | 5% | 1.7 |
| Medium glass wine | 175ml | 13% | 2.3 |
| Large glass wine | 250ml | 13% | 3.3 |
| Single spirit | 25ml | 40% | 1.0 |
UK low-risk guideline
The Chief Medical Officers’ low-risk guideline for both men and women is:
- No more than 14 units per week on a regular basis.
- Spread drinking over 3 or more days if you drink as much as 14 units.
- Include several drink-free days each week.
This calculator gives an estimate and can help with planning. It is not medical advice.
Why tracking units can help
- Improves awareness of how strong different drinks are.
- Helps avoid accidental over-drinking in social settings.
- Supports healthier routines and budgeting.
- Makes it easier to set and follow personal limits.
Practical tips to reduce weekly units
1) Swap strength, not necessarily the occasion
Choose lower-ABV options when possible. The same volume at lower strength can significantly cut units.
2) Alternate with alcohol-free drinks
Try water or alcohol-free alternatives between alcoholic drinks to pace yourself.
3) Measure at home
Free-pouring wine or spirits often increases unit intake. Use measured servings when possible.
4) Track for a few weeks
Even short-term tracking often reveals patterns and helps you make better choices.
Frequently asked questions
Is this calculator accurate?
It is accurate for the numbers entered. Real intake can vary if serving sizes are larger than expected or ABV differs by brand.
Do cocktails have more units?
Often yes. Cocktails can include multiple measures of spirits and liqueurs, so units can add up quickly.
Can I use this for weekly planning?
Yes. Enter your typical session and how many times per week it happens to estimate weekly total units.