Know how many units you’re drinking. This free alcohol units calculator turns a drink’s size and strength into units, shows the pure alcohol content, and compares your total to 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 Alcohol Units Calculator Works
This tool converts a drink’s 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 Scenarios
| 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 |
Alcohol Units Calculator FAQ
What is a UK alcohol unit?
A UK unit is defined as 10 ml (or 8 g) of pure alcohol. This calculator uses that definition to convert any drink’s volume and ABV into a standardized unit count, so drinks of different sizes and strengths can be compared directly.How is the 14-unit weekly guideline used here?
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 calculator shows your total units so you can see how it compares, but the guideline itself isn’t a hard safety cutoff.Why do beer and wine give different unit counts for similar-looking serving sizes?
Units depend on both volume and ABV, not size alone. A 175 ml glass of 13% wine contains more pure alcohol than a 330 ml can of 5% beer, because the higher strength multiplies out to more units despite the smaller volume.How are the calories estimated?
Alcohol supplies roughly 7 kcal per gram of pure alcohol. The calculator multiplies the estimated grams of alcohol by 7 to give an approximate calorie count, which doesn’t include calories from mixers, sugar, or other ingredients in the drink.Does choosing “One day” instead of “One week” change the units calculation?
No — the units math (volume × ABV ÷ 1000, times the number of drinks) is the same either way. The period selector only changes how the total is framed against session-level versus weekly guidance.Is any amount of alcohol completely risk-free?
No level of drinking is considered risk-free. This calculator is meant to build awareness of 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.