Alcohol Units and Weekly Intake Calculator

Convert a drink’s volume and strength into UK units, grams of ethanol, US standard drinks and Australian standard drinks at once — because a US standard drink is 1.77 UK units and the guidelines are not interconvertible.

The arithmetic, and where the density comes from

One standard drink, in every convention, both ways

Four national weekly thresholds in a common currency

The arithmetic is easy; the units are the problem

Counting alcohol is three multiplications. The UK formula is the one the NHS prints — strength (ABV) × volume (mL) ÷ 1,000 — and it is exact rather than approximate, because ABV is a volume fraction and a UK unit is defined as a volume: 10 mL of pure ethanol. A 568 mL pint at 5.2 per cent is 29.54 mL of ethanol, which is 2.95 units, and no density appears in that line at all.

Density appears the moment you leave the United Kingdom, because almost every other convention defines its drink by mass: a US standard drink is 14 g of ethanol, an Australian one and WHO’s reference drink 10 g. This page uses 0.789 g/mL, and it is worth seeing where that comes from. NIAAA defines the US standard drink as “0.6 fl oz or 14 grams of pure alcohol”; 0.6 US fluid ounces is 17.744 mL; 14 g in 17.744 mL is 0.789 g/mL. The figure is implied by a primary source’s own pair of numbers rather than taken on trust, and the same arithmetic shows the NHS’s familiar “8 g” to be a rounding of 7.89 g.

What follows is the only thing on this page that really matters. One US standard drink is 1.774 UK units and one Australian standard drink is 1.267. Kalinowski and Humphreys surveyed governmental definitions across 37 countries and found a range from 8 g in Iceland and the UK to 20 g in Austria — a factor of two and a half — so “a couple of drinks” has no fixed meaning across a border. Convert the four best-known weekly thresholds into grams of ethanol and they do not line up either: 110.5 g for the UK’s 14 units, 196 g for the US guidelines’ two drinks a day for men, 98 g for one a day for women, 100 g for the NHMRC’s 10 standard drinks. In UK units those are 14, 24.8, 12.4 and 12.7, so a total counted in one convention and judged against a guideline written in another can be out by nearly twofold in either direction.

The guidelines are also not saying the same kind of thing. The NHMRC caps a single day at 4 standard drinks as well as the week at 10, so a weekly total alone cannot be read against it. CDC’s framing of the US guidelines is that adults “should not drink alcohol or drink in moderation if they choose to drink alcohol”, and that “drinking less” is “better for your health than drinking more”. WHO went further on 4 January 2023: “there is no safe amount that does not affect health”, the evidence “cannot indicate the existence of a threshold” for alcohol’s carcinogenic effect, and “the risk to the drinker’s health starts from the first drop of any alcoholic beverage”. This page prints each threshold with the body that published it; it does not reconcile them, because they do not reconcile.

A total on this page is a number, not a diagnosis and not a verdict. It counts the ethanol in containers; whether anyone’s drinking is harming them is a clinical assessment that no arithmetic stands in for. This page does not exclude anything and screens for nothing. It converts a volume and a strength into four published conventions, and a weekly total below a national threshold is a comparison against that threshold rather than a statement about one person’s risk. This page renders no dose, no medication, no treatment regimen and no disposition. It computes the published total and prints the published thresholds with the body that published each one; what follows from the number is a clinical decision this page does not make. Every threshold on this page is printed with the body that publishes it, and not one of them is a cohort-derived accuracy figure: they are policy thresholds set by governments, not measurements of anything. If you are reading this about yourself and you are in distress or thinking about harming yourself, please contact your local emergency number or a crisis line now rather than treating a number as an answer: 999 or Samaritans on 116 123 in the UK and Ireland, 988 in the United States and Canada, or your local emergency service elsewhere.

Frequently asked questions

Related calculators

References

1. Calculating alcohol units. NHS, United Kingdom. Source of “One unit equals 10ml or 8g of pure alcohol”, of the arithmetic “strength (ABV) x volume (ml) ÷ 1,000 = units”, of the UK Chief Medical Officers’ threshold as the page states it (“men and women are advised not to drink more than 14 units a week on a regular basis”, spread over “3 or more days”), and of the worked drink values this page checks against: 3 units for a pint at 5.2 per cent, 2.1 for 175 mL of wine at 12 per cent, 1 for a 25 mL spirit measure at 40 per cent.
2. What is a standard drink? National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health. Source of the US definition — a standard drink is “defined in the United States as any beverage containing 0.6 fl oz or 14 grams of pure alcohol” — and of the four equivalences (12 fl oz of beer at about 5 per cent, 8 to 10 fl oz of malt liquor at about 7 per cent, 5 fl oz of table wine at about 12 per cent, a 1.5 fl oz shot of 80-proof spirits). Those two figures together IMPLY the density this page uses: 0.6 US fl oz is 17.744 mL, and 14 g in 17.744 mL is 0.789 g/mL.
3. Australian guidelines to reduce health risks from drinking alcohol. National Health and Medical Research Council, Australia, 2020. PDF read directly. Source of “A standard drink contains 10 grams of pure alcohol” and of Guideline 1: “healthy men and women should drink no more than 10 standard drinks a week and no more than 4 standard drinks on any one day”, which “does not apply to children and young people under the age of 18 years”.
4. Dietary Guidelines for Alcohol. Centers for Disease Control and Prevention, United States. Source of the US thresholds as CDC states them — “two drinks or less in a day” for men and “one drink or less in a day” for women — of the framing that adults of legal drinking age “should not drink alcohol or drink in moderation if they choose to drink alcohol”, and of “Drinking less. This is better for your health than drinking more”.
5. No level of alcohol consumption is safe for our health. World Health Organization Regional Office for Europe, 4 January 2023, published in The Lancet Public Health. Source of “there is no safe amount that does not affect health”, of the finding that “currently available evidence cannot indicate the existence of a threshold” for the carcinogenic effect, and of “the risk to the drinker’s health starts from the first drop of any alcoholic beverage”.
6. Low-risk drinking guidelines vary widely among countries. Stanford Medicine news release, April 2016, reporting Kalinowski A, Humphreys K. Governmental standard drink definitions and low-risk alcohol consumption guidelines in 37 countries. Addiction. 2016. The news release is what was read, not the paper: source of the range of standard drink sizes (“can range from 8 to 20 grams”), of Austria at 20 g and Iceland and the UK at 8 g, of WHO’s 10 g reference and the US 14 g, and of the weekly figures of 98 g for American women and 196 g for American men.

Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/