Your guide to alcohol units and strength

Lesley Dobson / 23 July 2020

Understanding how alcohol is measured, and knowing the maximum amount of alcohol you should drink a week, can help keep you healthy.



British Government guidelines recommend that men should not drink more than 14 units of alcohol each week, the same level as for women. If 14 units of alcohol a week is the amount you usually drink every week, make sure that you spread this amount over a week – ideally, over 3 days at the very least.

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How much is a unit of alcohol?

Alcohol is measured in units. One unit is 10 ml or 9g of pure alcohol. The amount of alcohol our bodies can cope with varies depending on your age, health and sex. However, it takes an average adult about an hour to process one unit of alcohol.

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What does alcohol by volume mean?

Some drinks are stronger in terms of alcohol content than others. The amount of alcohol in a bottle or can of drink is shown as a percentage of the content – or volume – of the drink.

You can find out how strong a drink is by looking at its label. This will show a percentage, followed by “ABV” which is short for alcohol by volume. Some labels just use the abbreviation “vol”. So if the label on a bottle says 12 ABV, it means that the content contains 12% pure alcohol.

This is a useful way of checking how much alcohol you’re consuming, rather than simply how much beer or wine. Some ales, for instance, are 3.5% ABV, but some stronger lagers can be as much as 5% or 6% ABV. This applies to wine too, which can range from 13% ABV to over 14%ABV.


How much alcohol is in your glass?

One unit of alcohol is about half a pint of normal lager, or one measure of spirits. There are about one and a half units of alcohol in a small (125ml) glass of wine.

However, unless you state precisely what strength beer you want, or whether you want a small or large glass of wine, you may be getting more alcohol than you bargained for.

If you drink a pint of strong lager, or a large glass of wine, you could be having more than three units of alcohol. This is at the upper limit of the guidelines for daily consumption for women.

Tip Before you down your beer or wine check its ABV.

Small glasses of wine usually contain 125ml (a slightly bigger glass can hold 175 ml), but a large glass contains 250ml. That’s a third of a bottle of wine, which can come to about three units of alcohol, in a single glass. Just by having two or three drinks, you could have downed a bottle of wine, and had nearly three times the recommended daily intake.

Tip Remember to say whether you want a small or large glass of wine.

Tip Drinking at home? Pour yourself small amounts, don’t fill your glass to the brim

Tip Pour your own drinks – it’s easier to keep track of how much you’ve had

How strong is your drink?

How alcohol is there in beer?

  • German Lager: 3% to 6% ABV
  • Bitter: under 3% to 7% ABV
  • India Pale Ale:  6-7% ABV
  • Stout: 5-10% ABV

How much alcohol is there in cider?

  • English ciders: 1.2% to 8.5% ABV
  • Continental ciders: 3.5% to 12% ABV
  • Perry: 4% to 8% ABV

How much alcohol is there in wine?

  • Table wine: 8-14% ABV
  • Claret: 6-10% ABV
  • Shiraz: 10-14% ABV
  • Rose:  10.5% ABV
  • White medium: 10.7% ABV
  • White dry: 11% ABV
  • Red medium: 11.5% ABV
  • White sparkling: 12% ABV
  • Cabernet, Pinot Noir: 11-14% ABV
  • Dessert wine: 14-20% ABV
  • Zinfandels: 17-22% ABV
  • Port: 20% ABV

Some wines, especially those produced in “New World” countries, such as the USA, Australia, South America and South Africa, have become more alcoholic over recent years because the hotter climates produce sweeter grapes. As sugar turns to alcohol during fermentation, it means stronger wine. Make sure you check the ABV on the label before buying. The result is that some of these wines now have an ABV of 17%. However, most wines range from 11% ABV to 14% ABV.

How much alcohol is there in spirits?

  • Bourbon 51-79% ABV
  • Brandy has 40-45% ABV
  • Gin has 37.5% ABV  
  • Vodka has 35-50% ABV
  • Whisky has 40-53% ABV

Calculating the units

Undoubtedly, units are confusing, and after a few glasses or pints, people tend not to care. If you are drinking bottled drinks or cans and they don’t have the number of units on its label you can easily work it out yourself using this simple method:

1. multiply the % alcohol content by the volume

2. divided by: 100 if volume stated in centilitres (cls) or

3. divided by: 1000 if volume is stated in millilitres (mls)

As a general guide you can use these estimates:

  • Pint of beer, ale or stout at 5% ABV: 2.8 units
  • Pint of lager at 5% ABV: 3 units
  • Pint of cider at 6% ABV: 3.4 units
  • Large glass (250ml) of wine at 12% ABV: 3 units

You can also find unit calculators online, such as this one from Alcohol Change.

Is alcohol getting stronger?

The strength of wines and beers has quietly been increasing over the decades without anyone batting an eyelid. In the 1970s, it used to be a lot easier to work out how much drink you were getting. A pint of beer used to equal two units, a shot of spirits one unit. Nowadays, beers, lagers and wines are all generally stronger and spirits are commonly sold in measures that are over a unit. For instance, in 1970 a bottle of wine may have been around 10 per cent in ABV (alcohol by volume) and now the same bottle is more likely to be around 13-14%. So what does this mean? Just a three per cent increase in a bottle of wine can have repercussions on your health. This works out to be an extra three units per bottle.

Equally, we have seen stronger lager become much more popular over the past couple of decades, with the growth of the five per cent ‘premium’ lager sector. It may be that the majority of consumers are not aware of ABV and don’t even notice. So despite a greater societal concern with being healthy... by stealth we are drinking more pure alcohol than ever.

Our glass sizes have also increased, from 100ml to 175ml and 250ml which could mean we are drinking three units in just one glass. This, coupled with the fact that home-pouring negates any notion of knowing how many units are being consumed, means that we may be putting our liver under undue pressure without knowing. For instance, a bottle of 14% wine contains 10.5 units and a pint of five per cent lager contains three units.

Alcohol and its impact on the liver

The liver is our largest internal organ. Among hundreds of jobs, it has to deal with the alcohol we drink. If we drink too much, our liver has to literally soak up the punishment. With few nerve endings to signal pain we wouldn’t know if our liver was complaining.

If somebody is drinking a lot on a regular basis, chances are that they will not feel anything happening until their liver has had enough. The harm to your liver at this stage will be severe – and could even be fatal. But your liver does have an incredible capacity to regenerate, and cutting down the amount you drink will improve your liver’s health.

This isn’t to say you should stop drinking altogether: rather, that you should be more conscious of the units consumed. It can be easy to underestimate how much alcohol you are drinking and often difficult to stop after a certain number of drinks, especially if somebody else is hosting and pouring.

To learn more about alcohol and the liver, visit the British Liver Trust at www.britishlivertrust.org.uk.

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.