Standard drinks and how much alcohol a pint of beer holds

ABV times volume tells you the alcohol

ABV means alcohol by volume. A beer at 5% ABV is 5% pure alcohol, so a 500 ml glass holds 25 ml of it. That one multiplication is the whole idea. Everything else, units and standard drinks included, is just a different way of counting those millilitres.

Brewers work out ABV from gravity readings taken before and after fermentation. Our guide to calculating ABV shows the formula. As a drinker you only need the number on the label or the menu.

Units and standard drinks are counting rules

Different countries count alcohol differently, which is why the advice you read online seems to disagree.

• UK unit: 10 ml, or 8 g, of pure alcohol. Units = ABV x volume in ml / 1,000.
• US standard drink: 14 g of pure alcohol, roughly a 355 ml can of 5% beer.
• 10 g standard drink: used in Australia and in many health guidelines.

Pure alcohol weighs about 0.79 g per ml, which is how you convert between millilitres and grams. Indian beer labels show volume and ABV but rarely a standard drink count, so it pays to know the sum yourself.

The differences matter when you read advice. Two drinks a day in US standard drinks is 28 g of alcohol. Two drinks in a 10 g system is 20 g. Same words, a 40% gap. Always check which drink size a guideline means before comparing it with your own habits.

A pint is not one drink

Here are common pours worked out in UK units, so you can check the arithmetic:

• 330 ml bottle at 5%: 16.5 ml alcohol, about 1.7 units.
• British pint (568 ml) at 4%: about 2.3 units.
• 500 ml brewpub glass at 6% (a typical IPA): 30 ml alcohol, 3 units.
• 650 ml bottle at 5%: about 3.3 units.
• 650 ml bottle of strong beer at 8%: 52 ml alcohol, about 5.2 units.

For comparison, a 30 ml peg of whisky at 42.8% holds about 12.8 ml of alcohol, roughly 1.3 units. So a single 650 ml bottle of strong lager holds about as much alcohol as four small pegs. Most people would never drink four pegs as casually as one big bottle.

Strength creeps up on craft drinkers

The catch for craft beer drinkers is that strength varies so widely. A wheat beer at 4.5% and a double IPA at 8.5% look similar in a 400 ml glass. The second carries nearly twice the alcohol. Imperial stouts and barleywines at 10 to 12% go further still, which is why good bars serve them in 200 to 250 ml measures.

Read the ABV on the board before you order, not after. Our guide to strong beer ABV walks through what a full evening adds up to.

How long the body takes to clear it

The liver processes alcohol at a fairly steady rate. A commonly quoted rough figure is about one UK unit an hour, though it varies with body size, sex, food and health. Nothing speeds it up. Coffee, a cold shower or a big breakfast do not lower the alcohol in your blood. Time does.

That has a practical edge. Three 500 ml glasses of 6% IPA add up to 9 units. On the rough hourly figure, some of that alcohol may still be in your blood the next morning. If you are driving early, count backwards.

Counting changes how you order

Most people who start counting units do not drink less beer they enjoy. They drink less beer they did not care about. They pick a smaller glass for the strong one, order a session beer first or switch to water halfway through the night. Some keep a running total on their phone.

Being able to taste the difference between a 4% and an 8% beer is a sensory skill too. Alcohol shows up as warmth, sweetness and body. Learning to read those signals is part of tasting properly.

Do the sum for your usual drink

Take the beer you order most often. Find its ABV and the pour size, multiply them and divide by 1,000. Write the answer on a note in your phone. Next time you order, you will know exactly what is in the glass.

Common questions

How many units are in a pint of beer?

A British pint (568 ml) of 4% beer holds about 2.3 UK units. At 6% the same pint holds about 3.4 units.

Is one beer one standard drink?

Rarely. A 355 ml can at 5% is close to one US standard drink. A pint or a 650 ml bottle is usually two to five, depending on strength.

How do I calculate units in a beer?

Multiply the ABV by the volume in millilitres and divide by 1,000. A 500 ml beer at 5% is 2.5 UK units.

Does coffee sober you up faster?

No. Coffee can make you feel more alert but your liver clears alcohol at the same rate. Only time lowers blood alcohol.