Work out alcohol units from a drink’s ABV and size. The tool turns volume and strength into UK units, shows the pure alcohol content, and compares your total with the low-risk weekly guideline.
1 UK unit = 10 ml of pure alcohol. A 330 ml beer at 5% is about 1.65 units.
For awareness only. The UK low-risk guideline is to keep within 14 units a week, spread over 3+ days, with drink-free days. No level of drinking is risk-free — for support, talk to a healthcare professional.
How Do You Calculate Alcohol Units From ABV?
Multiply the volume in ml by the ABV percentage, then divide by 1,000. A 750 ml bottle of 13% wine is 750 × 13 ÷ 1,000 = 9.75 units. A 568 ml pint of 5% beer is 2.84 units, and a 175 ml glass of 13% wine is about 2.3 units.
| Drink | ABV | Units |
|---|---|---|
| 330 ml can or bottle of beer | 5% | 1.65 |
| 568 ml pint of beer or cider | 5% | 2.84 |
| 175 ml glass of wine | 13% | 2.28 |
| 750 ml bottle of wine | 13% | 9.75 |
| 25 ml shot of spirits | 40% | 1 |
The Alcohol Units Formula
The tool converts volume and strength into UK alcohol units, then shows the pure alcohol content, an approximate calorie count, and how the total compares with the commonly cited 14-unit weekly low-risk guideline.
Formula: Units per drink = (Volume (ml) × ABV (%)) ÷ 1000. Total units = Units per drink × Number of drinks. Pure alcohol (g) = Total units × 8. Calories (approx) = Pure alcohol (g) × 7, rounded to the nearest whole number.
- Volume per drink: the size of one drink, in ml
- Strength (ABV): the drink’s alcohol by volume, as a percentage
- Number of drinks: how many drinks of that size and strength you’re totaling
- Period: whether the total represents one day/session or one week, used only to frame the comparison to the 14-unit weekly guideline
Example Totals for a Night or a Week
| Volume | ABV | Drinks | Total units |
|---|---|---|---|
| 330 ml (beer) | 5% | 4 | 6.6 units |
| 175 ml (wine) | 13% | 2 | 4.55 units |
| 25 ml (spirit shot) | 40% | 6 | 6 units |
| 440 ml (craft beer) | 7% | 3 | 9.24 units |
| 330 ml (beer) | 5% | 10 | 16.5 units |
Getting an Honest Total
The result is only as accurate as the volume and strength you enter, and both are easy to underestimate.
- Check the ABV on the label. Many wines and craft beers are stronger than you might guess.
- Measure home pours. A glass poured at home is often bigger than a pub’s 175 ml measure.
- Enter each drink separately rather than guessing a round total.
How Many Alcohol Units Per Week?
One UK unit is 10 ml, or 8 g, of pure alcohol. UK advice is to spread drinking over three or more days, so check your daily totals as well as the weekly figure.
Other countries define a standard drink differently, so these UK-based results won’t line up with US or Australian advice; the unit of alcohol article on Wikipedia compares national definitions. If you are pregnant, UK advice is not to drink at all. Talk to a GP if you take medication or find cutting down hard, and use the number as a prompt, not a verdict.
Common questions about alcohol units
What is a UK alcohol unit?
A UK unit is defined as 10 ml (or 8 g) of pure alcohol. The calculator uses that definition to turn any drink’s volume and ABV into a unit count, so drinks of different sizes and strengths can be compared directly.How many units are in a bottle of 13% wine?
A 750 ml bottle at 13% ABV contains 9.75 units (750 × 13 ÷ 1,000). At 12% ABV the same bottle is 9 units.How many units are in a 175ml glass of wine?
At 13% ABV, a 175 ml glass is about 2.3 units (175 × 13 ÷ 1,000 = 2.275). At 12% it is 2.1 units.How many alcohol units per week is the guideline?
The UK’s commonly cited low-risk guideline suggests staying within 14 units a week, spread over three or more days with some drink-free days. The guideline itself isn’t a hard safety cutoff.How are the calories estimated?
Alcohol supplies roughly 7 kcal per gram of pure alcohol, so the calculator multiplies the estimated grams by 7. That figure doesn’t include calories from mixers, sugar or other ingredients.Is any amount of alcohol completely risk-free?
No level of drinking is considered risk-free. The calculator is meant to show how units add up, not to suggest a safe amount. If you’re concerned about your drinking, talking to a healthcare professional is a good next step.Related Calculators
To look at drinking from a few more angles, try the blood alcohol (BAC) calculator for an estimate of how units and time might affect BAC, the alcohol calorie calculator to see the fuller calorie picture across drink types, or the sobriety calculator to track time since your last drink.