The recommended limit is 14 units of alcohol per week, spread across three or more days. This guideline, set by the UK Chief Medical Officers, applies equally to men and women. But what a “unit” actually looks like in your glass, and what the health evidence says about that number, is worth understanding in detail.
What Counts as One Unit
One unit of alcohol equals 8 grams (or 10ml) of pure ethanol. That’s a fixed measurement, but it doesn’t translate neatly into “one drink.” A single pint of higher-strength beer can contain 3 units, while a large glass of wine might hold 3 or more. The confusion between “a unit” and “a drink” is one reason people routinely underestimate how much they consume.
To calculate the units in any drink, multiply the volume in millilitres by the ABV (the percentage on the label), then divide by 1,000. A 175ml glass of 13% wine, for example, works out to about 2.3 units. A pint (568ml) of 4.5% beer is roughly 2.6 units. A single 25ml measure of 40% spirits is exactly 1 unit, though a double is obviously two. Using these figures, it becomes clear that just six pints of average-strength beer or six medium glasses of wine will push you past the 14-unit weekly limit.
Why the Limit Is Set at 14
The 14-unit guideline is designed to keep the risk of alcohol-related death at roughly 1%, a threshold the UK’s chief medical advisors considered acceptable when they revised the guidance in 2016. It’s not a line between “safe” and “dangerous.” It’s a point below which health risks remain relatively low for most adults. The World Health Organization stated in 2023 that no level of alcohol consumption is truly safe for health, noting that the cancer risk begins with the first drop and that no threshold exists at which alcohol’s carcinogenic effects switch on.
The advice to spread your drinking across three or more days matters too. Consuming all 14 units in one or two sessions carries different risks than spreading them out, particularly for your liver and cardiovascular system.
Cancer Risk at Different Drinking Levels
Alcohol is linked to cancers of the mouth, throat, oesophagus, liver, breast, and bowel. These risks exist even at light drinking levels. Data cited in the US Surgeon General’s Advisory put the numbers in practical terms: out of 100 women who have less than one drink a week, about 17 will develop an alcohol-related cancer over their lifetime. Among 100 women who have one drink a day, that number rises to 19. At two drinks a day, it reaches 22.
For men, the pattern is similar but starts from a lower baseline: 10 out of 100 for those who rarely drink, 11 for one drink a day, and 13 for two drinks a day. Heavy drinkers face dramatically higher risks for certain cancers. The risk of mouth and throat cancer is about five times higher in heavy drinkers compared to non-drinkers, and oesophageal cancer risk increases by a similar margin.
The WHO has noted that half of all alcohol-attributable cancers in Europe are caused by light and moderate drinking, not heavy consumption. This is partly because far more people drink moderately than heavily, so even a small increase in individual risk produces a large number of cancers across a population.
Effects on the Liver
A large UK study of over a million women found that cirrhosis incidence rises with total alcohol intake, even at moderate levels. Women consuming 15 or more drinks per week had roughly 3.4 times the cirrhosis risk compared to those having one to two drinks weekly. Among those drinking seven or more per week, daily consumption carried about 60% more risk than non-daily consumption, even when the weekly total was the same. In other words, how you distribute your drinking across the week makes a measurable difference to your liver.
Blood Pressure and Heart Health
Repeated binge drinking, defined as four or more drinks within two hours for women or five or more for men, can cause long-term increases in blood pressure. Even a single session of three or more drinks temporarily raises it. Over time, this puts extra strain on blood vessels and increases the risk of heart disease and stroke.
The encouraging side of this is that the effect is partly reversible. Heavy drinkers who cut back to moderate levels can lower their systolic blood pressure (the top number) by about 5.5 mm Hg and diastolic (the bottom number) by about 4 mm Hg. That reduction is comparable to what some people achieve with lifestyle changes like increasing exercise.
Pregnancy and Alcohol
The 14-unit guideline does not apply during pregnancy. The NHS recommends no alcohol at all if you are pregnant or planning to become pregnant. There is no known safe amount during pregnancy. Women who discover they are pregnant after drinking in early pregnancy are advised to stop drinking for the remainder of the pregnancy rather than worry about what has already been consumed.
Keeping Track in Practice
Most people don’t drink in neat, measurable units, which makes tracking harder than it sounds. A few practical reference points help:
- Pint of regular beer (4%-5%): about 2 to 2.8 units
- Medium glass of wine (175ml, 13%): about 2.3 units
- Large glass of wine (250ml, 13%): about 3.3 units
- Single measure of spirits (25ml, 40%): 1 unit
- Bottle of wine (750ml, 12%): about 9 to 10 units
A couple of pints after work three nights a week can easily total 15 to 18 units. Splitting a bottle of wine with a partner most evenings could mean 25 to 35 units a week. Home pours tend to be significantly larger than pub measures, so if you’re drinking wine at home, the actual amount in your glass is often closer to 250ml than 175ml.
Counting units for a week or two, even roughly, gives most people a clearer picture of where they actually stand relative to the 14-unit guideline. Many are surprised to find they’re over it.