Introduction
This alcohol unit calculator helps you figure out how many units of alcohol are in any drink. Just enter the drink's strength (ABV%) and its size, and the tool calculates the alcohol units. It works with 16 country standards, including the UK, USA, Australia, and Canada, so you get the right answer no matter where you live.
You can also use the reverse modes to find out how much of a drink you can pour to hit a target number of units, or what ABV a drink would need to reach a set unit count. Each result comes with a clear, step-by-step breakdown so you can see exactly how the numbers are calculated.
The built-in drink session tracker lets you log every drink you have in one sitting. Pick from common drinks like pints of lager, glasses of wine, and spirit measures, or add your own custom drinks. The tracker adds up your total units and shows a chart so you can see where your units are coming from. This makes it simple to keep track of how much you drink and stay within recommended guidelines.
How to Use Our Alcohol Unit Calculator
Enter details about your drink, like its strength and size, and this calculator will tell you how many alcohol units it contains based on your country's standard. You can also track a full drinking session and find the volume or ABV needed to hit a target number of units.
Country Standard: Pick your country from the dropdown menu. Each country in the list sets its own amount of pure alcohol for one unit. The calculator uses this number in every result it gives you.
Significant Figures: Choose how many digits you want in your results. The default is 3, which works well for most people.
Calculation Mode: Select how you want to calculate. "Standard" finds the units in a drink when you know the ABV and volume. "Reverse: Volume" finds how much you need to drink to reach a target number of units. "Reverse: ABV" finds what ABV a drink must be to reach a target number of units at a given volume.
Alcohol By Volume (ABV %): Type in the ABV of your drink. This is the percentage of the drink that is pure alcohol. You can find it on the bottle or can label.
Volume: Type in the amount of the drink. Then pick a unit of measurement from the dropdown next to it, such as millilitres, pints, or a named container like a 75cL bottle.
Target Units: This field is only used in the two reverse modes. Enter the number of alcohol units you want to reach, and the calculator will solve for the missing value.
Drink Session Tracker: Use the plus and minus buttons next to any drink in the catalog to count how many of each drink you have had. The session total at the top updates right away and shows your combined units.
Custom Drinks: If your drink is not in the catalog, type in its name, volume in mL, and ABV. Use the plus and minus buttons to set the quantity. Press "Add Another Drink" to track more than one custom drink in the same session.
What Are Alcohol Units?
An alcohol unit is a simple way to measure how much pure alcohol is in a drink. Different countries use different numbers.3 For example, in the UK, one unit equals 10 millilitres or 8 grams of pure alcohol.1 In the USA, one standard drink equals 14 grams.2 Knowing how many units you drink helps you understand how much alcohol your body actually takes in and can be paired with a BAC calculator to estimate your blood alcohol concentration.
How Alcohol Units Are Calculated
Every alcoholic drink has two key numbers: its volume (how much liquid there is) and its ABV, or alcohol by volume (the percentage of that liquid that is pure alcohol). To find the units, you multiply the volume in millilitres by the ABV written as a fraction (5% is 0.05), then by 0.789 (the density of alcohol in grams per millilitre), and divide by your country's unit size in grams. In the UK, where one unit is 10 millilitres of pure alcohol, the NHS works out units as ABV × volume in millilitres ÷ 1,000.1 A small glass of strong wine can have the same number of units as a large glass of weak beer. The percentage matters just as much as the size of the drink.
Why Tracking Alcohol Units Matters
Many people are surprised to learn what counts as a drink.2 A pint of strong lager has more units than a pint of light lager, even though the glasses look the same. Many countries' health guidelines set daily or weekly drinking limits, and some set both.3 In the UK, men and women are advised not to drink more than 14 units a week on a regular basis, and to spread those units over 3 or more days.1 Drinking more than 14 units a week over many years can raise your risk of liver disease, heart disease, stroke and some cancers.4
Standard Drinks vs. Alcohol Units
The terms "standard drink" and "alcohol unit" mean the same thing: a fixed amount of pure alcohol. The only difference is how much alcohol each country says that fixed amount is. The calculator's country table puts Australia and France at 10 grams, Canada at 13.45 grams and Japan at 20 grams.3 This means one "standard drink" in Japan contains more alcohol than one "unit" in the UK. When you compare your drinking to another country's guidelines, you need to use that country's definition.
Tips for Drinking Less
If you want to cut back, start by learning how many units are in your usual drinks. Choose lower-ABV options when you can. Use smaller glasses. Alternate alcoholic drinks with water. Keep track of your weekly total. Small changes add up over time and can make a big difference to your health. Alcoholic drinks often carry more calories than people expect.