About the NHS 14-unit guideline
In 2016 the UK Chief Medical Officers (CMOs) for England, Scotland, Wales and Northern Ireland updated the alcohol guidance to recommend that both men and women drink no more than 14 units per week to keep health risks at a low-risk level. Before 2016 the male limit was 21 units. The change reflected new evidence that even moderate drinking raises the risk of several cancers, particularly breast cancer, and that there is no completely safe level of alcohol consumption. The guidance also recommends spreading drinks over three or more days, having drink-free days each week, and never bingeing.
How the math works
- Each drink in your week contributes units = volume (ml) × ABV% divided by 1000. A pint of 4% lager is 568 × 4 / 1000 = 2.27 units.
- Multiply per-drink units by frequency per week. Three pints of 4% lager three nights a week = 3 × 2.27 × 3 = 20.4 units already.
- Sum across all drink types. The risk banner compares against the NHS bands - low-risk at or below 14 units, increasing risk between 14 and 35 (women) or 14 and 50 (men), and higher risk above 35 (women) or 50 (men) per week.
- Calories use ~60 kcal per unit (8g of ethanol at 7 kcal/g plus residual sugar). Cost uses rough off-licence UK prices in May 2026.
- The 5-year liver-disease risk multiplier is calibrated from cohort estimates - at 0-7 units/week the multiplier is roughly 1.0, rising to ~2-3x at 35 units, ~5-7x at 50 units and ~10x+ above 70 units versus non-drinkers.
Standard UK drink size cheat sheet
Common drink volumes and units in May 2026. Always check the label - many craft and continental options run far higher ABV than the UK pub standard.
| Drink | Volume | Typical ABV | Units |
|---|---|---|---|
| Half pint of standard lager | 284 ml | 4.0% | 1.14 |
| Pint of session ale | 568 ml | 3.5% | 1.99 |
| Pint of standard lager (Carling/Foster's) | 568 ml | 4.0% | 2.27 |
| Pint of premium lager (Stella/Heineken) | 568 ml | 5.0% | 2.84 |
| Pint of strong IPA | 568 ml | 5.6% | 3.18 |
| 440ml can of strong cider | 440 ml | 7.5% | 3.30 |
| Small glass of wine | 125 ml | 12.0% | 1.50 |
| Standard glass of wine | 175 ml | 12.0% | 2.10 |
| Large glass of wine | 250 ml | 13.0% | 3.25 |
| Bottle of wine (1 person) | 750 ml | 13.0% | 9.75 |
| Single spirit shot (England/Wales pub) | 25 ml | 40.0% | 1.00 |
| Single spirit shot (Scotland/NI standard) | 35 ml | 40.0% | 1.40 |
| Double spirit shot | 50 ml | 40.0% | 2.00 |
| Typical cocktail (double spirit + liqueur) | ~150 ml | ~18% | ~2.70 |
Common mistakes when tracking units
- Counting drinks, not units. "Three glasses of wine" sounds modest, but three large 250ml glasses of 13% wine is 9.75 units - 70% of your weekly limit in one night and a clear binge.
- Assuming all lager is 4%. Many craft beers and IPAs run 5.5-8% ABV. A pint of 6% craft beer is 3.4 units, half as much again as a 4% pint.
- Free pours at home. A "single" at home is often 35-50ml rather than the 25ml pub measure, doubling the unit count without you noticing.
- Forgetting the weekend skew. If you drink 0 units Mon-Thu and 18 units Fri-Sat, you are still over the 14-unit limit AND bingeing - the spread matters, not just the total.
- Counting "low-alcohol" beers as zero. Drinks labelled 0.5% ABV are essentially alcohol-free, but anything 1-2.8% still contributes units (and calories).
- Ignoring strong cider. A 440ml can of 7.5% white cider is 3.3 units - more than a pint of standard lager and far more calories.
The formula explained
This calculator applies four chained formulas:
1. units(drink) = volume_ml × ABV% / 1000
2. weekly_units = SUM over drinks of (units × frequency_per_week)
3. risk_band = low if ≤ 14; increasing if ≤ 35 (F) / 50 (M); higher otherwise
4. calories(drink) = units × 60 kcal (approx)
The unit formula is the UK government standard (8g of pure ethanol = 1 unit; 1 ml of pure ethanol weighs 0.789g, so 8g = 10ml of pure ethanol = 10ml × ABV in a 100% scale). The 14-unit/week threshold comes from the 2016 CMO Low Risk Drinking Guidelines. The 35-unit and 50-unit increasing/higher-risk thresholds are NHS classification rather than statute.
To verify the math, plug in a pint (568ml) at 4% ABV: result should be 568 × 4 / 1000 = 2.272 units. A 175ml glass at 13.5%: 175 × 13.5 / 1000 = 2.36 units. A 25ml shot at 40%: 25 × 40 / 1000 = 1.00 unit.
Frequently asked questions
What is the NHS 14-unit weekly limit?
The UK Chief Medical Officers recommend that both men and women drink no more than 14 units per week to keep health risks at a low level. The guidance was unified at 14 units for both sexes in 2016. To stay low-risk you should spread those 14 units over three or more days, have several drink-free days, and avoid binge drinking (6+ units for women or 8+ units for men in a single session).
How do I calculate alcohol units?
UK alcohol units = (volume in ml × ABV%) / 1000. A pint (568ml) of 4% beer is (568 × 4) / 1000 = 2.272 units. A large 250ml glass of 13% wine is (250 × 13) / 1000 = 3.25 units. A 25ml single shot of 40% spirit is (25 × 40) / 1000 = 1 unit. Multiply each drink by how many times per week you have it, then sum.
How many units are in a pint of beer or lager?
It depends on strength. A pint (568ml) of 3.5% session lager is 1.99 units. A pint of standard 4% lager is 2.27 units. A pint of 4.5% premium lager is 2.56 units. A pint of 5% lager (Stella, Heineken) is 2.84 units. A pint of 5.6% IPA is 3.18 units. A half pint contains half the units of a pint at the same strength.
How many units are in a glass of wine?
A small 125ml glass of 12% wine is 1.5 units. A standard 175ml glass of 12% wine is 2.1 units. A large 250ml glass of 12% wine is 3 units, rising to 3.4 units at 13.5% ABV. A 750ml bottle of 13% wine is 9.75 units, so finishing a bottle alone in one evening counts as a binge for both men and women.
How many units are in a single shot of spirit?
A 25ml single shot of 40% spirit (vodka, gin, whisky, rum, tequila) is exactly 1 unit. A 35ml single shot (common in Scotland, Northern Ireland and many city pubs) is 1.4 units. A 50ml double is 2 units. Higher-strength spirits (50% bourbon, 57% navy rum) scale up. Cocktails with double spirits plus liqueurs typically run 2-3 units per drink.
What counts as binge drinking?
NHS and CMO guidance defines binge drinking as 6 or more units in a single session for women and 8 or more for men. That is roughly 3 large 250ml glasses of 12% wine, or 4 pints of 4% lager. Regular bingeing sharply raises short-term and long-term risks even if your weekly total is below 14 units.
How many calories are in alcohol?
One UK alcohol unit contains roughly 56-65 calories. A pint of 4% lager is about 180 kcal, a 175ml glass of 12% wine is about 150 kcal, a 25ml single spirit is about 60 kcal (more once you add a sugary mixer). Drinking 14 units a week adds roughly 800-900 kcal/week - an entire extra meal. Alcohol is also nutrient-poor (empty calories).
What are the health risks of drinking above 14 units?
NHS classifies low-risk as 14 units/week or less, increasing risk as 14-35 units (women) or 14-50 (men), and higher risk above 35 (women) or 50 (men). Increasing-risk drinkers face higher chances of high blood pressure, type 2 diabetes, breast cancer and several other cancers. Higher-risk drinkers add liver disease (cirrhosis, alcoholic hepatitis), pancreatitis, heart muscle damage, brain damage, dependence and 3-5x higher all-cause mortality.