When calculating the size, strength and units of an alcoholic drink, you’ve got a fair few numbers to consider to stay within the recommended guidelines.
These numbers can make it all too confusing, and before you know it, it’s like a mathematical equation. To help you keep track, here’s a breakdown of what they all mean.
Taking beer or lager as an example, glass size and measurements are fairly straightforward compared to some other drinks, such as spirits or wine. Lager, beer or ale is usually offered as either a pint or half pint.
And although the strength of wine may vary, if you drink in a pub you’ll usually be offered a measurement – 175 ml or 250ml.
So far, so good. But then it gets trickier – how do you know how much alcohol by volume (ABV) is in your drink and does that affect how many units you’re drinking?
ABV is expressed as a percentage (usually on the packaging or menu) of how much total alcohol is in your drink.
A unit is a measurement of 10ml or 8g of pure alcohol. It takes about one hour for your body to process one unit.
A pint of strong lager, for example, can be as much as 6% ABV, whereas some ales can be as low as 3.5%. Depending on the strength of your drink, the amount of units it contains will vary.
To calculate how many units are in your drink yourself, you can do this sum:
Strength of your drink (ABV %) multiplied by the amount (ml) divided by 1000 = the number of units
So, if you have a pint (568ml) of strong lager (6% ABV), then you’re looking at over three units in your drink. When you apply this to sensible drinking guidelines, you can see why it’s so easy to go over.
Guidelines vary from country to country, but in the UK:
And to throw another formula into the mix, could the shape of your glass affect how quickly you drink your beverage? Some research suggests it could influence your drinking speed and also your perception of how much drink your glass holds.
The results of this small study showed that people drank alcoholic drinks faster from a curved glass than those who drank from a straight glass. People also had more trouble guessing the midpoint on the curved glass than the full glass.
How much we can read into this is debatable due to the small study size and potential for other factors affecting the results. However, it’s still an interesting observation about our drinking habits.
The truth is, when you’re out with friends enjoying a couple of drinks, these numbers and dimensions are the last thing on your mind. Research shows that, in general, people don’t know enough about what they are drinking. This is partly down to the labelling on the packaging or bottle. But it’s also a sign that people either don’t understand what these mean or aren’t keeping track of their drinking.
It’s no wonder sticking within the guidelines can seem tricky. So, what can you do to make things easier?
The numbers are there for a reason – to protect your health and keep you and others safe. Taking a bit of time to understand them could help you keep your drinking in check and your health on track.