Calculate my units
How alcohol units are calculated
A UK unit is a fixed quantity of pure alcohol — 10 ml, or 8 grams — chosen because it is roughly what an average adult processes in an hour. Because it measures the alcohol itself rather than the drink, it lets you compare a pint of lager with a glass of wine on the same scale.
A 250 ml glass of 13% wine works out at 13 × 250 ÷ 1,000 = 3.25 units. Every drink on this page is calculated the same way, using the strength and serving size shown.
| Drink | Units | Calories from alcohol |
|---|---|---|
| Pint of lager (568 ml, 4%) | 2.3 | ~127 |
| Pint of ale or stout (568 ml, 5%) | 2.8 | ~159 |
| Bottle of beer (330 ml, 5%) | 1.7 | ~92 |
| Small wine (125 ml, 13%) | 1.6 | ~91 |
| Large wine (250 ml, 13%) | 3.3 | ~182 |
| Bottle of wine (750 ml, 13%) | 9.8 | ~546 |
| Single spirit (25 ml, 40%) | 1.0 | ~56 |
Those figures count the calories in the alcohol itself. A whole drink usually contains more, because beer, wine and mixers carry carbohydrate too. The NHS puts a standard 175 ml glass of 12% wine at up to 158 kcal and a pint of 5% beer at up to 222 kcal — against roughly 118 kcal and 159 kcal from the alcohol alone in those same drinks.
What the 14-unit guideline actually says
The UK Chief Medical Officers recommend that adults drink no more than 14 units a week. Since 2016 that figure has been the same for men and women, replacing the older split of 21 and 14 as evidence on long-term risk was revised.
Fourteen units is roughly six pints of average-strength lager, or six medium glasses of wine, across a whole week.
It is also worth being clear about what the guideline claims. It describes a low-risk level, not a safe one. The CMOs are explicit that there is no level of regular drinking that carries no risk at all — 14 units is the point below which risk stays low for most people, not a threshold where harm begins.
Why your drinks are probably stronger than you think
Most people underestimate their intake, and usually not through dishonesty. Three things drive the gap.
Wine has got stronger
Table wine was commonly 11% a few decades ago and is now frequently 13–14%. A large glass of modern wine is 3.25 units on its own — nearly a quarter of the weekly guideline from a single pour.
Home measures are not pub measures
A pub single is 25 ml and a standard wine glass is measured. Poured at home, both tend to be considerably more generous, and the difference compounds quickly across a week.
“A glass of wine” is not a unit
The phrase gets used as though it means one unit. It has not for a long time. Only a small 125 ml glass of relatively weak wine comes close, and few people drink that.
The calories are easy to overlook
Alcohol contains about 7 kcal per gram — nearly as much as pure fat, and considerably more than protein or carbohydrate. That works out at roughly 56 kcal per unit before any mixers, which is how this calculator arrives at its figure.
Drinking the full 14 units a week therefore adds around 784 kcal, and that is a floor rather than a typical figure — tonic, cola and juice add more, as do cocktails. These calories bring no protein, vitamins or minerals with them.
There is a second effect that matters if you are watching your weight. Your body cannot store alcohol, so it prioritises metabolising it over other fuels. Everything else you have eaten waits its turn, which is part of why regular drinking makes a calorie deficit harder to hold.
Weekly totals can hide the pattern
A weekly number can look reasonable while concealing something the guidance treats as a separate risk. Drinking a large amount in one session — conventionally more than six units for women or eight for men in a single sitting, so roughly two large glasses of wine or three pints — raises the immediate risk of accident and injury, regardless of how modest the rest of the week looks.
Ten units on a Saturday and nothing else is within the weekly guideline. It is not within the spirit of it.
If you want to cut down
Small structural changes tend to work better than resolve. Setting fixed drink-free days gives the week a shape. Measuring pours at home rather than free-pouring often reveals a surprising amount on its own. Alcohol-free alternatives have improved considerably and remove the awkwardness of holding nothing. And because drinking is largely habitual, changing the cue — the route home, the glass, the time of evening — is frequently more effective than resisting the drink itself.
If you are worried about your drinking or someone else's, your GP is a good starting point and these conversations are more routine than people expect. Drinkline offers free, confidential advice on 0300 123 1110, weekdays 9am–8pm and weekends 11am–4pm.
Frequently asked questions
Sources and further reading
- Department of Health. UK Chief Medical Officers’ Low Risk Drinking Guidelines. London, 2016. gov.uk/government/publications/alcohol-consumption-advice-on-low-risk-drinking — the 14-unit weekly guideline and the reasoning behind it. Link checked 19 October 2026 (title page only — see the note below).
- National Health Service. Calculating alcohol units. NHS, 2025. nhs.uk/live-well/alcohol-advice/calculating-alcohol-units — one unit is 10 ml or 8 g of pure alcohol, the unit formula used above, and the 14-units-a-week guideline. Checked 18 October 2026.
- National Health Service. Calories in alcohol. NHS, 2025. nhs.uk/live-well/alcohol-advice/calories-in-alcohol — alcohol provides about 7 kcal per gram, and the whole-drink figures quoted for wine and beer. Checked 18 October 2026.
- National Health Service. Alcohol support. NHS, 2025. nhs.uk/live-well/alcohol-advice/alcohol-support — the Drinkline number and opening hours given in the disclaimer. Checked 18 October 2026.
- Wood AM, Kaptoge S, Butterworth AS, et al. Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599,912 current drinkers in 83 prospective studies. The Lancet, 2018;391(10129):1513–1523. pubmed.ncbi.nlm.nih.gov/29676281 — the evidence on where long-term risk begins to rise. Record checked 19 October 2026.
- National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis and management of physical complications (CG100), 2010, updated 2017. nice.org.uk/guidance/cg100 — why withdrawal from dependence needs medical supervision. Link checked 19 October 2026 (title page only — see the note below).
- National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis, assessment and management of harmful drinking and alcohol dependence (CG115), 2011. nice.org.uk/guidance/cg115 — assessment and treatment pathways in the UK. Link checked 19 October 2026 (title page only — see the note below).
How to read the dates above. Checked means we opened that page and confirmed it still carries the wording quoted beside it. Record checked means we confirmed the citation against the PubMed record — authors, journal and year — but the article itself sits behind a publisher paywall and we have not re-read the full text. Link checked (title page only) means the link resolves to the right document, but the text is only readable in a browser, so we have not re-read what it says. The dates are when a person actually opened the source; they are not bumped when a release is packaged.