This alcohol unit calculator is here to help you never ask yourself the question: "how much is a unit of alcohol again?", as well as so much more! You will not only find the precise definition of one unit of alcohol, but also a snippet of the story behind it. There is also the main functionality of this tool - a panel that allows you to calculate all your alcohol units from last night, including your customized cocktail, and a favorite beer size! You can also check if you have exceeded the safe limits in the 'Do I drink too much?' section.

What is an alcohol unit?

An alcohol unit is a measure defined a portion of an alcoholic beverage that contains exactly 10ml (8g) of pure ethyl alcohol. Alcohol units have been used - especially in the United Kingdom - since 1987, to help people keep an eye on their drinking and provide health guidelines regarding safe alcohol consumption. The US and Australia prefer to use the term 'standard drink'.

One unit of alcohol is also the amount that, an average, a healthy, adult body can break down within an hour - so theoretically there should be no alcohol left in your blood after that time (though you may still feel some of the effects of the drink, such as thirst). In real life, it strongly depends on individual's metabolism, sex, age, weight and even your stress level at that time. You can roughly assess the content of alcohol in your blood after particular time here.

How much is a unit of alcohol?

You can work out the number of alcohol units in your drink using the following formula (works for any drink):

[strength (ABV) * drink volume (ml)]/1000

(ABV - alcohol by volume - is a measure of pure alcohol as a percentage of the total volume of liquid in the drink.)

To help you visualise the term 'one unit of alcohol' we can use a few popular examples:

  • A single shot of spirit (40%, 25ml) is one unit of alcohol
  • A standard glass of wine (12%, 175ml) is two alcohol units
  • A pint of standard beer (5%, 568ml) is three units of alcohol
  • One portion of port wine (20%, 50ml) is nearly one unit of alcohol
  • One James Bond-style Vesper martini is five units!

It's not so hard to confuse 'one beer' with 'one alcohol unit', right? That's why we've got you covered with this alcohol units calculator!

How to use the alcohol unit calculator?

  1. Take a look at the calculator panel on the left. You will see a list of the basic, most popular alcoholic beverages. You begin by typing in your portions or...
  2. on Advanced mode at the bottom of the alcohol unit calculator to see more options. You can now add more sizes of beer, your custom drink or bar mixes, etc.
  3. Now, you should now fill in the fields of the number of drinks you've had. Be frank about it - the result is only for you. :)
  4. The result at the bottom is your result for the United Kingdom's alcohol unit definition (just for the record - 10ml, 8g).
  5. You can also convert the outcome into your country's alcohol unit term, just choose the place you're interested in.

One unit of alcohol doesn't mean the same everywhere

Alcohol consumption guidelines belong to a larger group of health recommendations, which also vary from country to country. Guidelines are based on research made in a particular place, and, while we're talking about alcohol and food intake recommendations, they depend strongly on a products' availability, social conditions and, very often, tradition. For example, for many countries it is hard to imagine a wedding without a traditional wedding spirit. The goal is to make recommendations closer and more personalised, which increases the chance the population will follow them.

That is why, if you search for alcohol consumption recommendations, you have to pay attention to the country you're in and the country you're referring to. The good news is that health ministries now mark the content of pure alcohol in a particular beverage using simple, apparent icons. And, luckily, the basic units remain the same, so if you know your drinks volume and proof - you're all set!

Here, in the calculator panel, you can check how much is a unit of alcohol in your country compared to the UK one. You've also got the amount of pure alcohol in 'one unit' in brackets next to it.

International Alliance For Responsible Drinking has guidelines for particular countries.

So, I calculated it... But do I drink too much?

The UK's National Health Service guidelines state:

  • Both men and women should not drink more than 14 units of alcohol per week.
  • You should spread your drinking across the week into at least 3 days if you regularly drink as much as 14 units.
  • While consuming large amounts of alcohol at once, keep in mind some basic rules to lower the risk of harming yourself: drink more slowly, drink with food and alternate alcohol with non-alcoholic beverages.
  • Pregnant women or those who are trying for a baby should avoid any alcohol. The same applies to people with certain medical conditions and underage people.
  • There is no strict boundary between safe and dangerous drinking. Therefore you should keep your drinking to the lowest possible level.
  • If you're concerned with your drinking, don't hesitate to seek professional help. Addiction is not fun at all and can make you lose much more than money.

If your result is still unclear to you, you can check out an easy, a 3-item test called AUDIT-C. It will help you define if your drinking fits within the normal range.

Aleksandra Zając, MD
Low alcohol beer/cider
Standard beer/cider
Strong beer/cider
Standard glass of wine (175ml)
Glass of champagne (150ml)
Alcopop (275ml)
Shot of spirit (single, 25ml)
Your result
Your country
United Kingdom (8g)
Alcohol units
Check if you are within your weekly limit - go to the Do I drink too much? section.
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