Let’s begin at the start - what is a unit? A unit of alcohol is 10milliletres (ml) or 8 grams of pure alcohol. As different drinks have different strengths and serving sizes, units are a great way to understand how much alcohol you’re drinking over the course of a certain time period.
It’s said to take around one hour for the body to metabolise (break down) one unit of alcohol and process it out of the bloodstream. This is approximate, of course, and varies depending on your body size, age, gender, metabolic rate and so on. We all know people who seem to sober up much quicker than others, but as a general guideline, 1 unit = 1 hour.
The standard suggested amount of units per week is 14, spread out across the week, for both men and women. That’s around 6 pints of 4% beer, or 6 medium glasses of standard red wine.
How do you work out the number of units in a drink?
You can work out the number of units of alcohol in a drink with some fairly simple maths. Just get the volume of the drink in millilitres (ml) and divide it by 1,000. Then multiply that number by the % ABV number.
For example, let’s consider a pint of our Pilsner which comes in at 5% ABV. A pint is the equivalent of 568ml. So we’d do 568 divided by 1,000 = 0.568.
Multiply that by 5 and you get 2.84, which we’ll call 2.8. So our Pilsner has 2.8 units of alcohol in each pint.
Or, a half a pint of the same pilsner would be 1.4 units.
Stronger drinks like stouts, of course, are going to have higher unit counts. It comes naturally with the strong, rich and often sweet flavour profile, and explains why, alongside porters, they’re often served in smaller glasses like halves or 2/3 pints.
Most stouts sit between 5% to 8% ABV, although the odd Irish dry stout can be 3.5%. Imperial stouts can get really rather high, sometimes going up to 11% – do be careful!
If you’re looking to cut down on the units and take it a bit easy over the course of an evening, why not try a session beer? These are usually lighter to the taste and lower in alcohol – between 3 and 5 percent. Our Session Pale clocks in at 3.8% ABV.
Let’s get the calculator out (or just look on the back of the can!) – that means a pint of Session contains 2.15 units and a 330ml can has 1.25 units. (It’s like being back at school… but there’s beer!)
Drink driving and the legal alcohol limit
Finally, something you might be wondering when planning a journey – how do you know if you’re over the limit for driving?
There’s no definitive way, unfortunately. We can’t say “1 drink will keep you under the limit” because it depends on the strength of the drink, your body type, your metabolism, what you’ve eaten recently, and your stress levels at the time.
The safest way, of course, is to avoid alcohol completely if you’re driving. There are loads of alcohol-free beers available these days alongside mocktails and soft drinks for you to enjoy.
*You can find out more about legal limits for driving at DrinkAware.