What's a standard drink? Colin Angus on units and guidelines

A standard drink is the set amount of pure alcohol a country uses to count drinks. A UK unit is 8 grams, a US standard drink is 14 grams, and in a 2015 survey of 37 countries the most common size was 10 grams. To count your own, multiply your drink's size by its strength (the % on the label), add up an ordinary week, and compare it with your own country's guideline, read as a lower-risk line rather than a safe one.

In 2016 the UK's Chief Medical Officers brought the men's weekly guideline down from 21 units to 14, the same as women's. "There's quite a lot of sort of kickback," Colin Angus remembered on The Alcohol 'Problem' Podcast five years later (The Alcohol 'Problem' Podcast, chapter at 44:11). Angus, then a senior research fellow in the Sheffield Alcohol Research Group, builds mathematical models of how drinking and alcohol policies affect health. For the review behind the new guideline, he and his colleagues modeled how the risk of dying from drinking changed with different amounts and patterns.

Why one line for both? At the same amount, he explained, women face a slightly higher risk for biological reasons, but "men do more stupid stuff", like getting drunk and getting hurt, and at lower amounts the two roughly cancel out.

The steps below cover counting your real drink, reading your country's number, and choosing a cut that counts.

Count the drink you really pour

1. Learn your country's drink

The UK counts in units; most other countries count in "standard drinks", and the size isn't standard at all. In 2015 the researchers Agnieszka Kalinowski and Keith Humphreys searched for definitions from 75 governments and found them for 37. The most common size was 10 grams of pure alcohol, and the range ran from 8 to 20 grams (Kalinowski & Humphreys, 2016). Today's official sizes in four English-speaking countries:

• UK: one unit is 8 grams (10 ml) of pure alcohol, the alcohol in a single 25 ml shot at 40% (NHS).
• Australia: 10 grams. That's roughly 285 ml of full-strength beer at 4.9%, 100 ml of wine at 13% or 30 ml of spirits (NHMRC, 2020).
• Canada: 13.45 grams. That's a 341 ml bottle of 5% beer, a 142 ml glass of 12% wine or a 43 ml shot of spirits (CCSA, 2023).
• US: 14 grams. That's 12 ounces of regular beer at 5%, 5 ounces of wine at 12% or 1.5 ounces of spirits at 40% (NIAAA).

So "two drinks" in an American article is about three and a half UK units. Check whose drink a number is counted in.

2. Work out your real drink: size times strength

"One of the things that gets confusing for many people is that in their minds, a glass equals a drink," the psychologist R. Lorraine Collins of the University at Buffalo told NPR's Life Kit (NPR Life Kit).

Two numbers decide what's in your glass: its size and its strength, the % ABV on the label. The NHS gives the sum for units: strength × milliliters ÷ 1,000. A pint of 5.2% lager comes to about 3 units, and the same pint at 3.6% to 2. A standard 175 ml glass of 12% wine is 2.1 units, and a 750 ml bottle at 13.5% is 10 (NHS). Strength matters as much as size: a 12-ounce craft beer at 10% is two US standard drinks (NIAAA).

To compare across countries, use grams. Since one UK unit is 10 ml or 8 grams of alcohol, any drink's grams are its milliliters × its % ÷ 100 × 0.8. That bottle of 13.5% wine holds about 80 grams: 10 UK units, about 8 Australian standard drinks, or about 6 Canadian or US ones (our arithmetic from the official sizes).

At home, few glasses are marked. Fill yours with water to the level you usually pour, then tip it into a measuring cup. That's our own method, and it works with any glass.

3. Count a whole ordinary week

The UK's experts chose a weekly guideline over a daily one "because most people do not drink every day" (UK Chief Medical Officers, 2016). So count a whole ordinary week, day by day, in your real drinks, and note your heaviest day as well as the total.

Read your guideline as a line on a slope

4. Know how your country's number was set

Angus described two ways to set a guideline from evidence. The Canadian approach puts the line where your risk of death starts to rise above a non-drinker's. The Australian approach accepts some risk, as we do with driving, and puts the line where drinking at that level all your life gives "a 1% lifetime chance of dying as a result of" it. His team ran both, for men and for women, and for different drinking patterns, which produced "big tables with whole slews of numbers". The UK's 14 units, he said, sits somewhere in the middle of them.

What four countries say now:

• UK (2016): no more than 14 units a week on a regular basis, spread over three or more days (UK Chief Medical Officers). That's about six pints of average-strength beer or ten small glasses of lower-strength wine (NHS).
• Australia (2020): no more than 10 standard drinks a week and 4 on any one day, which keeps the lifetime risk of dying from alcohol-related disease or injury below 1 in 100 (NHMRC).
• Canada (2023): a continuum. Two standard drinks a week or fewer is low risk, 3 to 6 is moderate, and 7 or more is increasingly high (CCSA).
• US (2026): no number. The Dietary Guidelines for 2025 to 2030 say "Consume less alcohol for better overall health" (HHS & USDA). The old 2 drinks a day for men and 1 for women belong to the replaced 2020 to 2025 edition (USDA & HHS).

Where a country splits by sex, follow its own figure. Canada's public summary adds that "health risks increase more quickly at 7 or more standard drinks per week for females."

5. Spread it out, and plan the big night

The weekly total isn't the whole story. Angus's example: two people drink 14 units a week, one as two units every day, the other all 14 in one day. They "probably have similar chronic risks, but their risks of alcohol poisoning or their risks of injury are very different". That's why the UK's guideline says to spread drinking over three or more days.

For a single occasion, the UK's Chief Medical Officers set no unit figure; they suggest drinking less and more slowly, with food and water, and planning how you'll get home. In the US, binge drinking typically means 5 or more drinks for a man, or 4 or more for a woman, in about two hours, in 14-gram US drinks (NIAAA). Canada's guidance says not to exceed 2 drinks on any day. When you're driving, the right number is none.

6. Read "lower risk" as lower risk

Tom Chivers, a science writer who joined Angus on the same episode, objected to the guideline's "hard cutoff": "this is a sliding scale of impact", and 13 units instead of 15 isn't a cliff edge. Angus put it from the modeler's side: "I don't like them being called safe drinking guidelines."

Australia's guideline "does not represent a 'safe' or 'no-risk' drinking level" (NHMRC), and WHO's European office has said, "We cannot talk about a so-called safe level of alcohol use" (WHO Europe, 2023). Health bodies say there's no amount of alcohol that is free of cancer risk.

On whether small amounts protect, Angus called himself "a bit agnostic", and agreed that nothing in the evidence says a non-drinker should start drinking for their health; our article on moderate drinking covers the red-wine question. Some people have their own number, whatever the guideline: if you're pregnant or trying to conceive, stop for that time and talk to your midwife or doctor. Some medicines and alcohol don't mix, so ask your pharmacist or doctor about yours.

Cut from where you are

7. Count each drink you cut

If your week sits well above the line, the line can feel pointless. Angus's point runs the other way: "the additional risk of drinking one more unit is more for someone who's drinking 50 units a week than for someone who's drinking 20 units a week." Canada's guidance says the same: "Any reduction in alcohol use is beneficial", and people drinking at high levels "have even more to gain" (CCSA, 2023). If 14 feels out of reach, cutting from where you are still counts. Our guides on how to drink less and drinking every night turn that into a plan.

There's one exception to cutting fast. If your body may have got used to alcohol, stopping or cutting down quickly can make you unwell, sometimes seriously. Talk to a doctor before you change how much you drink. A doctor can help you cut down or stop safely, usually without a hospital stay.

If, after stopping or cutting down, you get shaky, sweaty, sick or very anxious in the hours after your last drink, talk to a doctor before going further. If you, or someone with you, notice a fit, confusion (not knowing where you are or what day it is), or seeing or hearing things that aren't there, get medical help straight away. Don't wait.

8. Make the pour smaller

One of the easiest cuts is in the glass. Angus co-wrote two UK experiments on serving sizes (Kersbergen et al., 2018). In a lab, 114 students and staff drank about a fifth less in an hour when each serving was a quarter smaller. In a Liverpool bar on quiz nights, 164 local people drank about a third less when servings were roughly a third smaller: two-thirds of a pint instead of a pint, and 125 ml of wine instead of 175. Each result held in only one of the two ways the researchers analyzed it, so treat the size as a rough guide.

At home the evidence is weaker. In a trial with 260 UK households, smaller wine glasses went with about 6.5% less wine, which could have been chance, and smaller bottles didn't clearly help (Mantzari et al., 2022). For swapping some drinks for alcohol-free ones, see our article on non-alcoholic beer.

Start with the glass you already own

The 2016 kickback Angus remembered was about a number. He sees that number as a guide for an average person, and "obviously, not many people are actually average." If you do one thing this week, measure your usual pour with water.

To do this with your own week, try the 1h Protocol to Reduce Your Drinking. Its free first chapter counts your week in your own country's drinks, checks the drink you really pour and asks how your body reacts, then names your pattern and gives you one first step. The full program is practical education and takes about an hour. You leave with a personal plan built from your answers, your goal counted in your country's drinks, a moment card for your lock screen, a fourteen-day sheet, and your day-7 and day-14 reviews in your calendar. Check-in emails follow on days 1, 7, 14 and 30. Start free

Frequently asked questions

What counts as a standard drink?

A fixed amount of pure alcohol, set by each country: 8 grams in a UK unit, 10 in Australia, 13.45 in Canada and 14 in the US (NIAAA). A glass can hold one, two or more, depending on its size and strength.

How many units are in a bottle of wine or a pint?

A 750 ml bottle of 13.5% wine is 10 UK units. A pint of 5.2% lager is about 3 units, and a pint at 3.6% is 2 (NHS). For any drink, multiply its strength by its milliliters and divide by 1,000.

How many drinks is too much in a week?

Each country draws its own line. The UK's is 14 units, Australia's 10 standard drinks with no more than 4 on any day, and Canada calls 7 or more a week increasingly high risk; the current US guidelines give no number. Our guide on how to drink less starts from your own week.

Is 14 units a week safe?

It's a lower-risk line, not a risk-free one. The UK's Chief Medical Officers set 14 units as the level that keeps health risks low, and at or above it the lifetime risk of dying from an alcohol-related condition would be expected to be at least 1% (UK Chief Medical Officers, 2016). Health bodies say there's no amount of alcohol that is free of cancer risk.

Why do countries give different limits?

Partly because their drinks differ in size, from 8 to 20 grams in a 2015 survey of 37 countries (Kalinowski & Humphreys, 2016). They also accept different levels of risk, as Angus's two approaches show, and were set in different years: Canada moved to a continuum in 2023, and the US dropped its daily limits in January 2026. Use your own country's current guidance.

Sources

This article draws on Colin Angus's and Tom Chivers's interviews on The Alcohol 'Problem' Podcast, R. Lorraine Collins on NPR's Life Kit, the national guidance of the UK, Australia, Canada and the US, and the studies listed below.

• Alcohol risk, guidelines and messaging, with Tom Chivers and Colin Angus (podcast episode, The Alcohol 'Problem' Podcast, 2021)
• Americans Are Drinking More During The Pandemic. Here's How To Cut Back (podcast episode with R. Lorraine Collins, NPR Life Kit, 2020)
• NHS, Alcohol units (public health page, reviewed 2024)
• NIAAA, What is a standard drink? (public health page, updated 2025)
• NIAAA, Understanding alcohol drinking patterns (public health page, updated 2026)
• Kalinowski & Humphreys, Governmental standard drink definitions and low-risk alcohol consumption guidelines in 37 countries (survey of government guidance collected in 2015, Addiction, 2016)
• UK Chief Medical Officers' Low Risk Drinking Guidelines (national guidance, 2016)
• Canada's Guidance on Alcohol and Health: Final Report (national guidance, CCSA, 2023)
• Canada's Guidance on Alcohol and Health, public summary (public brochure, CCSA, 2023)
• Australian guidelines to reduce health risks from drinking alcohol (national guidance, NHMRC, 2020)
• Dietary Guidelines for Americans, 2025-2030 (national guidance, HHS and USDA, 2026)
• Dietary Guidelines for Americans, 2020-2025 (national guidance, replaced in 2026)
• WHO Europe, No level of alcohol consumption is safe for our health (news release, 2023)
• Kersbergen et al, Reducing the standard serving size of alcoholic beverages prompts reductions in alcohol consumption (two randomized experiments, 114 and 164 adults, UK, 2018)
• Mantzari et al, Impact of wine bottle and glass sizes on wine consumption at home (randomized trial, 260 UK households, 2022)