What Is a Standard Drink, and How Much Alcohol Is in Yours?

A “standard drink” is a fixed amount of pure alcohol (ethanol), and the amount differs by country: 14 g in the US, 13.45 g in Canada, 10 g in Australia, and 8 g in a UK unit. A drink as served often holds more than one: a large glass of wine or a strong craft beer can be two or three standard drinks. Counting grams of alcohol, rather than glasses, is the only way to compare.

This article is general information, not medical advice.

Working Out the Alcohol in a Drink

Alcohol content is labelled as alcohol by volume (ABV). Ethanol weighs about 0.789 g per millilitre, so:

grams of alcohol = volume (mL) × ABV (%) ÷ 100 × 0.789

Drink	Volume	ABV	Alcohol	US standard drinks
Beer	355 mL (12 fl oz)	5%	14 g	1.0
Wine	150 mL (5 fl oz)	12%	14 g	1.0
Spirits	44 mL (1.5 fl oz)	40%	14 g	1.0
Large glass of wine	250 mL	13%	26 g	1.8
Strong IPA, pint	568 mL	7%	31 g	2.2

The first three rows are the US National Institute on Alcohol Abuse and Alcoholism’s (NIAAA) examples of one standard drink. The UK’s National Health Service (NHS) counts in units of 10 mL of pure alcohol (about 8 g).

How Much Is Low Risk?

Guidance has become stricter as evidence on alcohol and cancer has grown:

• Canada (Canada’s Guidance on Alcohol and Health, 2023). Risk rises along a continuum: 2 standard drinks or fewer a week is likely to avoid alcohol-related harm; 3 to 6 a week increases the risk of several cancers, including breast and colon cancer; 7 or more significantly increases the risk of heart disease and stroke. More than 2 drinks on one occasion increases the risk of injury and harm.
• UK (NHS). Adults are advised not to drink more than 14 units (about 112 g) a week on a regular basis, spread over three or more days.

Not drinking at all is the lowest-risk choice for health, and the guidance is clear that each additional drink increases risk.

Following It in Kaizora

Dietary Alcohol is kept as a mass of ethanol, in grams, and shown in grams or your country’s standard drinks, chosen by your region: 14 g in the US, 8 g for a UK unit, 13.45 g in Canada, or 10 g in Australia. It comes from the drinks you log on Food Log, or from Cronometer’s import. A habit such as “at most 2 standard drinks in 7 days” follows Canada’s lowest-risk level; set it in drinks and it’s checked in drinks. See Habits and How Does Alcohol Affect Your Sleep?

The Short Version

• A standard drink is 14 g of alcohol in the US, 13.45 g in Canada, 10 g in Australia; a UK unit is 8 g.
• Grams of alcohol = mL × ABV ÷ 100 × 0.789.
• Canada’s guidance puts 2 drinks or fewer a week at low risk; the UK says no more than 14 units a week.

Sources

• National Institute on Alcohol Abuse and Alcoholism, What Is a Standard Drink?
• Canadian Centre on Substance Use and Addiction, Canada’s Guidance on Alcohol and Health (2023).
• National Health Service, Alcohol units.