Alcohol Units Calculator UK

Calculate units in any drink using the UK formula. Track your weekly total against the NHS 14-unit safe limit. Use quick presets or enter custom drinks.

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Understanding UK Alcohol Units

The alcohol unit system is a uniquely British measurement tool introduced in 1987 to help people understand how much alcohol they are actually consuming. One unit of alcohol equals 10ml or 8 grams of pure ethanol — regardless of what drink it comes from. This standardised system allows you to compare alcoholic drinks of different strengths and volumes fairly.

The formula is straightforward: Units = (ABV% × Volume in ml) ÷ 1000. So a 250ml glass of wine at 13% ABV contains: (13 × 250) ÷ 1000 = 3.25 units. This simple calculation is the basis of the UK's entire public health alcohol guidance.

NHS Recommended Weekly Limits

The Chief Medical Officers for the UK updated alcohol guidelines in 2016. The current recommendation is that both men and women should not regularly drink more than 14 units of alcohol per week. This represents a change from previous guidance that allowed men a higher limit — new evidence showed alcohol's cancer risk applies equally to both sexes.

Crucially, the NHS advises that these 14 units should be spread across three or more days. "Saving up" your weekly allowance and drinking it all in one or two sessions — known as binge drinking — significantly increases health risks even if the total weekly units are below 14.

What Does 14 Units Actually Look Like?

Many people underestimate how quickly units accumulate. Here are common drinking scenarios and their unit counts:

This demonstrates why tracking units is valuable — social drinking can quickly exceed safe levels without feeling excessive.

Common Drink Units Reference Table

DrinkSizeABVUnits% of Weekly Limit
Beer / Lager (pint)568ml4%2.316%
Strong Beer (pint)568ml5%2.820%
Wine (small glass)125ml13%1.611%
Wine (medium glass)175ml13%2.316%
Wine (large glass)250ml13%3.2523%
Bottle of wine750ml13%9.7570%
Single spirit25ml40%1.07%
Double spirit50ml40%2.014%
Prosecco125ml11%1.410%
Champagne125ml12%1.511%
Alcopop275ml4%1.18%
Craft IPA (pint)568ml6.5%3.726%

Health Risks of Exceeding the Weekly Limit

The NHS states there is no completely safe level of alcohol consumption. However, drinking above 14 units per week on a regular basis increases the risk of a wide range of serious health conditions. These include liver cirrhosis and liver cancer, breast cancer (alcohol is a known carcinogen for breast tissue), bowel cancer, mouth and throat cancers, heart disease and stroke, high blood pressure, and pancreatitis.

Mental health is also significantly affected. Regular heavy drinking is linked to anxiety, depression, sleep disorders, and dependency. Alcohol use disorder affects over 600,000 people in England alone, according to NHS data. Alcohol is involved in around 1 in 5 emergency hospital admissions in the UK.

Understanding Alcohol Metabolism

Your liver can process approximately 1 unit of alcohol per hour, though this varies between individuals based on age, sex, body weight, liver health, and whether you have eaten. Women generally metabolise alcohol more slowly than men due to lower body water content and different enzyme levels. There is no way to speed up alcohol metabolism — time is the only solution.

Blood Alcohol Concentration (BAC) determines how alcohol affects you. In the UK, the drink-drive limit is 80mg of alcohol per 100ml of blood in England and Wales (35 micrograms per 100ml of breath). Scotland has a lower limit of 50mg per 100ml of blood. Even one unit can impair reaction time and judgement — never drink and drive.

Tips for Reducing Alcohol Intake

If you want to reduce your weekly units, practical strategies include: choosing lower-ABV drinks, alternating alcoholic drinks with water, setting a units budget before going out, having alcohol-free days each week (the NHS recommends this), opting for smaller measures, and using an alcohol unit tracker like this calculator to stay aware of your consumption.

If you are concerned about your drinking, the NHS advises speaking to your GP. Free resources include Drinkline (0300 123 1110), Alcoholics Anonymous, and the FRANK alcohol information service. These services provide confidential support without judgement.

Frequently Asked Questions

What is one unit of alcohol UK?
One unit of alcohol in the UK equals 10ml (8g) of pure alcohol. The formula is: units = (ABV% x volume in ml) / 1000. For example, a standard 25ml measure of 40% spirits contains exactly 1 unit. A pint (568ml) of 4% beer contains 2.3 units. The unit system helps you compare very different drinks on a common scale.
How many units per week is safe UK?
The NHS recommends that both men and women should not regularly drink more than 14 units per week. This should be spread over 3 or more days rather than consumed in one or two sessions. 14 units is roughly equivalent to 6 pints of average-strength beer or 10 small glasses of low-strength wine.
How many units are in a bottle of wine?
A standard 750ml bottle of wine at 13% ABV contains approximately 9.75 units of alcohol. This means that drinking a full bottle of wine alone accounts for nearly 70% of the recommended weekly limit of 14 units. A medium 175ml glass of 13% wine contains 2.3 units.
How long does alcohol stay in your system?
The liver processes approximately 1 unit of alcohol per hour. A person who has drunk 6 units (e.g. 3 pints of beer) will take roughly 6 hours to process the alcohol. This varies with age, weight, gender, and whether food has been eaten. The morning after a heavy session, significant alcohol often remains in the bloodstream — this is a serious concern for driving.
What counts as binge drinking in the UK?
The NHS defines binge drinking as drinking over 8 units in a single session for men, and over 6 units for women. This is roughly 3 pints of strong beer for men or 2 large glasses of wine for women. Binge drinking significantly increases risk of accidents, alcohol poisoning, cardiovascular events, and long-term health complications.
Are alcohol-free drinks completely safe?
Most alcohol-free drinks contain 0.0% to 0.5% ABV and are considered safe for most people. At 0.5% ABV, a 330ml can contains just 0.165 units — negligible for most adults. They are an excellent alternative for reducing alcohol intake. Always check with your doctor if you are pregnant, on medication, or in recovery from alcohol dependency.
Does eating food affect alcohol absorption?
Yes, significantly. Eating before or while drinking slows the absorption of alcohol into the bloodstream. High-fat and high-protein foods delay gastric emptying, giving the liver more time to metabolise alcohol. This results in a lower peak blood alcohol concentration and a slower rise in intoxication. Never drink on an empty stomach.
What are the health risks of regularly exceeding 14 units per week?
Regularly exceeding 14 units per week increases risk of liver disease (including cirrhosis and liver cancer), breast cancer, bowel cancer, mouth and throat cancers, heart disease, stroke, high blood pressure, pancreatitis, and mental health problems including depression and anxiety. The NHS states there is no completely safe level of alcohol consumption.

Content reviewed by Mustafa Bilgic (MB) | Last updated: February 2025 | Sources: NHS UK, Chief Medical Officers UK, Drinkaware