Standard Drink Calculator

The Standard Drink Calculator converts any alcoholic drink into standard drinks (or units) using just its volume and ABV. Because every country defines a "standard drink" as a fixed mass of pure alcohol, this tool lets you put beer, wine, spirits, and cocktails on one consistent scale — and compare the very same drink across the US, UK, Australia, Canada, and Europe.

What is a Standard Drink?

A standard drink is a unit of measurement that always contains the same amount of pure alcohol, no matter what you are drinking. It exists so that a pint of beer, a glass of wine, and a shot of spirits can be compared fairly. In the United States, one standard drink contains 14 grams of pure alcohol, which works out to roughly a 12 oz (355 mL) beer at 5%, a 5 oz (148 mL) glass of wine at 12%, or a 1.5 oz (44 mL) shot of 40% spirits — all of these contain about the same amount of alcohol.

Standard Drink Formula

Every definition reduces to grams of pure alcohol, so the calculation takes two short steps.

The number 0.789 g/mL is the density of ethanol, which converts a volume of alcohol into a mass. The denominator in Step 2 depends on where you are: 14 g in the US, about 8 g in the UK, 10 g in Australia and most of Europe, and 13.6 g in Canada.

Standard Drink Definitions by Country

Because the definitions differ, the same drink counts as a different number of standard drinks depending on the country — a UK "unit" is the smallest, so any drink will show the most units there, while the US 14 g definition gives the fewest.

Typical ABV of Common Drinks

How Many Calories Are in Alcohol?

Pure alcohol supplies about 7 calories per gram — almost as much as fat (9 cal/g) and more than carbohydrate or protein (4 cal/g). These are "empty" calories with no nutritional value, and they do not include the sugars in mixers, juices, or the drink itself. A standard 14 g drink therefore carries roughly 98 calories from the alcohol alone, which is why this calculator reports the alcohol calories for your serving.

Low-Risk Drinking Guidelines

Health bodies publish guidelines to help people keep their drinking in a lower-risk range. They differ between countries and between men and women:

• United States: Up to 2 drinks per day for men and 1 per day for women.
• United Kingdom: No more than 14 units per week, spread over three or more days.
• Australia: No more than 10 standard drinks per week and no more than 4 in a single day.
• Canada (2023): 2 standard drinks or fewer per week is considered low risk; 3–6 is moderate risk.

No amount of alcohol is completely risk-free. These figures are guidelines to reduce harm, not a target or a "safe" allowance.

How to Use This Calculator

1. Choose a standard: Pick the country or region whose definition you want to use — the US (14 g), UK (10 mL units), Australia (10 g), Canada (13.6 g), or Europe/WHO (10 g).
2. Enter the serving size: Type the volume and select its unit (mL, fluid ounces, litres, or pints).
3. Enter the ABV and quantity: Add the alcohol by volume percentage from the label and how many of these drinks you had.
4. Click Calculate: See the number of standard drinks, the animated drink-unit visual, pure alcohol grams and calories, and a side-by-side comparison across all five definitions.

Frequently Asked Questions

What is a standard drink?

A standard drink is a fixed amount of pure alcohol used to measure consumption consistently across different drinks. In the United States one standard drink contains 14 grams (0.6 fl oz) of pure alcohol, which is roughly a 12 oz (355 mL) beer at 5%, a 5 oz (148 mL) glass of wine at 12%, or a 1.5 oz (44 mL) shot of spirits at 40%.

How do you calculate standard drinks?

First find the grams of pure alcohol: multiply the volume in millilitres by the ABV divided by 100, then by 0.789 (the density of ethanol). Then divide that mass by the grams of alcohol in one standard drink for your region. For example, a 355 mL beer at 5% contains 355 × 0.05 × 0.789 = 14 g of alcohol, which is exactly 1 US standard drink.

Why do standard drinks differ by country?

Each country sets its own definition. The US uses 14 g of pure alcohol per standard drink, the UK uses units of 10 mL (about 8 g), Australia and most of Europe use 10 g, and Canada uses 13.6 g. Because of this, the same glass of wine counts as a different number of standard drinks depending on where you are.

How many calories are in alcohol?

Pure alcohol provides about 7 calories per gram, almost as much as fat. These are the calories from the alcohol itself and do not include sugars or mixers. A drink containing 14 g of pure alcohol therefore carries roughly 98 calories from alcohol alone.

What is the ABV of common drinks?

Typical values are around 4–6% for beer, 11–14% for wine, 15–20% for fortified wine, and 37–45% for spirits such as vodka, whisky, gin, and rum. Always check the label, since craft beers and strong wines can be considerably higher.

How many standard drinks is safe per week?

Guidelines vary. The UK suggests no more than 14 units a week, Australia no more than 10 standard drinks a week and 4 in a day, and Canada's 2023 guidance considers 2 drinks or fewer per week to be low risk. No level of alcohol is completely risk-free, so these figures are guidelines rather than safe limits.

Additional Resources

• Standard Drink - Wikipedia
• Unit of Alcohol - Wikipedia