Join the iPhone beta
Join the Android betaThe calculator above tracks two things at once as you log a round: a running UK units total (millilitres x ABV / 1000, added up as you pour) and an estimated blood alcohol curve for the evening, built from your weight, sex and age on the same model Abvy's app runs. It isn't a breathalyzer and doesn't measure anything about your body - it calculates from population averages, so two people with identical inputs can clear alcohol at genuinely different rates in real life.
The 14-unit guideline
UK Chief Medical Officers advise both men and women to stay under 14 units a week on a regular basis, spread across three or more days rather than in one or two heavy sessions. It's a long-term health guideline, not a single-night limit and not a driving threshold - a heavy Saturday can sit well under 14 units and still leave you far over the legal limit to drive hours later.
How many units in a pint?
A pint of average-strength (4-4.5%) beer or lager is roughly 2.3-2.6 units; a stronger 5.5% pint is closer to 3.1 units. Wine and spirits scale the same way - volume x ABV / 1000 - which is exactly what the running total above does with whatever you actually pour.
The drink-drive limit
The legal limit in England, Wales and Northern Ireland is 80 milligrammes of alcohol per 100 millilitres of blood; Scotland sets a lower limit of 50 milligrammes per 100 millilitres. No calculator, including this one, can tell you whether you're under it on any given night - individual absorption varies too much to call safely. If you're driving, the only certain number is zero.
FAQ
A pint (568 ml) of 4.5% beer works out to about 2.6 units - the formula is volume in ml x ABV / 1000. A stronger craft pint at 6% is closer to 3.4 units. Log the drinks you actually had above and the running total does the maths for you.