Alcohol Units

ABV, volume, and regional definitions

Alcohol guidance is often given in UK units, US standard drinks, or Australian/NZ standard drinks. Each definition packs a different amount of pure alcohol into “one unit/drink.” This calculator combines drink volume, ABV (%), and quantity using the factor for the system you select.

Outputs are educational arithmetic — not a breathalyser, not legal advice, and not a green light to drive.

Idea behind the maths

Pure alcohol volume ≈ drink volume × ABV%. Regional unit systems divide that pure alcohol by their standard amount (for example the UK unit is 10 ml of pure alcohol). Larger serves or higher ABV increase the count; quantity multiplies a single-serve result.

Worked example

A 568 ml UK pint at 4% ABV contains about 22.7 ml pure alcohol → roughly 2.3 UK units. A 355 ml US beer at 5% ABV is typically around one US standard drink, but checking with the calculator beats guessing.

Common mistakes

• Counting “one glass of wine” as one unit regardless of pour size and ABV.
• Mixing UK units with US standard drinks in the same diary.
• Assuming home measures match bar measures — see Drink Glasses.

FAQs

Does this track blood alcohol?

No. Metabolism, body size, and time matter; only drink content is estimated here.

Where are health guidelines?

Follow your local public-health recommendations; they change and differ by country.

Related: Drink Glasses, Liquids, Percentage.