Alcohol Units Calculator
Calculate UK alcohol units or US standard drinks from the information you know.
Choose the calculation that matches your data. The definitions are not interchangeable.
Your drink details
Selected definition
1 UK unit = 10 ml pure alcohol
US standard drinks are calculated separately from grams of alcohol. Select the US mode above.
Total alcohol units
Across 1 serving · 500 ml at 5% ABV
Beverage composition
How is this calculated?
Equipment guide
Read the ABV
Check the alcohol strength (ABV) on the bottle, can or packaging.
Measure your serving
Use a measuring glass or jug to find the actual volume poured.
Count each serving
Multiply by the number of identical servings you have.
Calculation & assumptions
UK units = Volume (ml) × ABV (%) × Servings ÷ 1000
US standard drinks = Alcohol (g) × Servings ÷ 14
Each mode uses its own inputs and definition. No blood-alcohol or clearance-time estimate is made.
Frequently asked questions
What does this calculator calculate?
The UK mode calculates alcohol units from beverage volume and ABV. The US mode calculates standard drinks from the known mass of pure alcohol. Each mode can multiply one serving by a number of identical servings.
Which inputs should I use?
For UK units, enter the actual beverage volume per serving and the ABV percentage printed on the label. For US standard drinks, enter the known grams of pure alcohol per serving, not the total weight of the beverage. Set the number of identical servings.
Why do UK units and US drinks differ?
They use different definitions and are not interchangeable. One UK unit represents 10 ml of pure alcohol. The US standard drink definition uses about 14 g of pure alcohol. This tool deliberately keeps volume-based UK calculations and mass-based US calculations separate; it does not silently assume an ethanol density for cross-conversion.
Does the volume include the whole bottle?
Use the amount you actually measure as one serving. If you enter the volume of an entire bottle, one serving means that whole bottle. Do not enter the whole bottle volume and also multiply by the number of glasses from that same bottle.
Does this tell me when I can drive?
No. Units or standard drinks cannot establish a safe driving time, blood-alcohol level or alcohol clearance time. This calculator does not estimate those quantities.
More questions (6)
What does the Alcohol Units calculate?
It calculates UK units using volume and ABV, or US standard drinks using grams of pure alcohol. Select the definition matching your data.
Which values should I enter?
UK mode uses volume in ml or L, ABV from 0 to 100 percent, and a positive whole number of identical servings. US mode uses grams of pure alcohol per serving and the same serving count. The inactive mode does not affect the result.
What formula does this calculator use?
UK units = volume in ml × ABV percentage × servings ÷ 1000. US standard drinks = grams of pure alcohol × servings ÷ 14. Litres are converted using 1 L = 1000 ml.
Why might my result differ from another source?
Check country-specific definitions, actual serving volume, beverage strength, pure alcohol mass, serving count and display rounding. This tool does not automatically convert UK units to US standard drinks.
Does the result update automatically?
Yes. Changing the active input values or mode updates the result, metrics and worked formulas immediately. Invalid active inputs clear the outputs and disable exports; the mode selector remains visible.
What are the software input limits?
Volume per serving must be greater than zero and no more than 100,000 ml (100 L); ABV 0–100 inclusive; pure alcohol mass per serving 0–100,000 g; servings a whole number from 1–1000. These are software bounds, not consumption recommendations. Zero ABV and zero pure alcohol mass produce zero alcohol equivalents.
Sources & References
NHS · UK alcohol unitsVolume and ABV calculation; 10 ml per unit.
NIAAA · US standard drinks14 g pure alcohol per standard drink.References provide context, not endorsement.
Page information
Updated: October 27, 2026