Standard Drink Size: What Is a Standard Drink?
The standard drink size in the US is 14 grams of pure alcohol. That matches a 12 oz beer at 5%, 5 oz of wine at 12% or 1.5 oz of spirits at 40% alcohol by volume (ABV). A UK unit is 10 mL (about 8 g), Australia, New Zealand and Ireland use 10 g, and Canada 13.45 g. The grams of alcohol in a standard drink let you estimate your BAC from your own drinks and weight.
The 14 gram US drink
One US standard drink holds 14 g of pure ethanol, a figure the National Institute on Alcohol Abuse and Alcoholism (NIAAA) also gives as 0.6 fl oz. For beer, 355 mL x 0.05 x 0.789 g per mL comes to 14.0 g, as do the wine and spirits pours. NIAAA also counts each drink below as one, and every range in the table includes 14 g.
| Drink (NIAAA one-drink amount) | Typical ABV | Pure alcohol |
|---|---|---|
| Malt liquor or hard seltzer, 8 to 10 oz | about 7% | 13.1 g to 16.3 g |
| Fortified wine (sherry, port), 3 to 4 oz | about 17% | 11.9 g to 15.9 g |
| Liqueur or aperitif, 2 to 3 oz | about 24% | 11.2 g to 16.8 g |
| Brandy or cognac, 1.5 oz | about 40% | 14.0 g |
These amounts "may not reflect customary serving sizes," NIAAA adds.
An average drinker clears roughly 0.015% BAC each hour, so the hours needed to reach zero depend on the peak. How much one standard drink raises BAC differs at each body weight. In one study, equal grams peaked at 0.050% on beer and 0.077% on vodka tonic, one reason no fixed number of drinks gets a person drunk.
Standard drink size by country
Standard drink size runs from about 8 g in a UK unit to 14 g in the US, so a count from one country does not carry over to another. The fourth column counts one 12 oz (355 mL) can of 5% beer.
| Country | Measure | Pure alcohol | 12 oz can of 5% beer | Set by |
|---|---|---|---|---|
| United States | standard drink | 14 g (0.6 fl oz) | 1.00 drink | NIAAA |
| United Kingdom | unit | 10 mL (about 8 g) | 1.77 units | National Health Service (NHS) |
| Australia | standard drink | 10 g | 1.40 standard drinks | Department of Health |
| New Zealand | standard drink | 10 g (at 20 °C) | 1.40 standard drinks | Food Standards Code 2.7.1 |
| Ireland | standard drink | 10 g | 1.40 standard drinks | Health Service Executive (HSE) |
| Canada | standard drink | 13.45 g (17.05 mL) | 1.04 standard drinks | Health Canada |
Ireland skips units; the HSE writes "We do not measure alcohol in units". An Irish pint of 4.5% beer counts as 2 Irish standard drinks (2.02 by the math), yet only 1.44 US drinks. The HSE puts a 750 mL bottle of 12.5% wine at just over 7 Irish standard drinks.
Why a UK unit is 8 grams
The NHS defines a unit by volume, as 10 mL of pure alcohol. At 0.789 g per mL that is 7.89 g, which the NHS and the HSE round to 8 g. So count UK units with the NHS units formula, ABV x mL ÷ 1,000, not grams ÷ 8. For the 79.9 g in a 750 mL bottle of 13.5% wine, grams ÷ 8 gives 9.99 but the formula gives 10.1 units.
A unit count measures the glass, not the driver, and the UK drink driving limit in breath and blood is set in neither units nor drinks.
Grams of alcohol in a shot by country
A US shot of 1.5 oz at 40% ABV holds 14.0 g of alcohol. A UK single of 25 mL holds 7.9 g, so one US shot is close to two UK singles.
| Measure at 40% ABV | Pure alcohol | US drinks |
|---|---|---|
| US shot, 1.5 oz (44 mL) | 14.0 g | 1.00 drink |
| UK single, 25 mL (1 unit) | 7.9 g | 0.56 drinks |
| UK large single, 35 mL (1.4 units) | 11.0 g | 0.79 drinks |
| Irish single, 35.5 mL | 11.2 g | 0.80 drinks |
| Canadian pour, 43 mL | 13.6 g | 0.97 drinks |
How many drinks in a bottle, can or box
A 750 mL fifth of 40% spirits holds about 17 US standard drinks. Wine at 12% gives about 5 per 750 mL bottle and 20 per 3 L box. US spirits come in 25 authorized sizes from 50 mL to 3.75 L (27 CFR 5.203). Wine sizes include 750 mL and 3 L, with only whole liters above 3 L (27 CFR 4.72).
The table applies the label method below to common containers.
| Container | Pure alcohol | US drinks | UK units | AU, NZ, IE drinks | Canada drinks |
|---|---|---|---|---|---|
| 12 oz beer can, 5% | 14.0 g | 1.00 drinks | 1.77 units | 1.40 drinks | 1.04 drinks |
| 16 oz beer pint, 5% | 18.7 g | 1.33 drinks | 2.37 units | 1.87 drinks | 1.39 drinks |
| 750 mL wine, 12% | 71.0 g | 5.07 drinks | 9.00 units | 7.10 drinks | 5.28 drinks |
| 3 L wine box, 12% | 284.0 g | 20.29 drinks | 36.00 units | 28.40 drinks | 21.12 drinks |
| 375 mL spirits, 40% | 118.4 g | 8.45 drinks | 15.00 units | 11.84 drinks | 8.80 drinks |
| 750 mL fifth, 40% | 236.7 g | 16.91 drinks | 30.00 units | 23.67 drinks | 17.60 drinks |
| 1.75 L spirits, 40% | 552.3 g | 39.45 drinks | 70.00 units | 55.23 drinks | 41.06 drinks |
NIAAA rounds its own counts to 17 for a fifth, 8½ for 375 mL and 5 for a 750 mL bottle of wine. It also calls the 375 mL spirits bottle a "pint", which holds about 8.45 drinks; a 16 oz (473 mL) beer pint holds 1.33.
How many shots in a fifth and a handle
At 1.5 oz (44 mL) per shot, a 750 mL fifth pours about 16.9 shots and a 1.75 L bottle (often called a handle) 39.4. Those counts describe the bottle, not a night. Fewer than 8 breaths a minute is one of the alcohol poisoning signs, and it calls for 911, or the emergency number where you are, straight away.
Glasses of wine in a bottle or box
Wine bottles of 750 mL pour about 5 glasses of 5 oz, and 3 L boxes about 20. The grams of alcohol in wine depend on strength as much as pour: a 5 oz glass holds 14.0 g at 12% but 15.8 g at 13.5%. The Australian Government counts a 4 L cask of 13.5% wine as 43 standard drinks.
How to count standard drinks from a label
To count standard drinks from a label, multiply the mL by the ABV, then by 0.789 for grams, then divide by your country's drink size.
- Read the volume in mL and the ABV.
- Multiply mL by the ABV as a decimal (13.5% is 0.135) to get mL of ethanol.
- Multiply by 0.789 g per mL to get grams.
- Divide by 14 in the US, 10 in Australia, New Zealand and Ireland, or 13.45 in Canada. For UK units, use ABV x mL ÷ 1,000.
Take one 750 mL bottle of wine at 13.5% ABV. Its ethanol is 750 mL x 0.135 = 101.25 mL, which weighs 101.25 x 0.789 = 79.9 g. That makes 79.9 ÷ 14 = 5.71 US drinks and 79.9 ÷ 10 = 8.0 Australian, NZ or Irish drinks. Canada counts 79.9 ÷ 13.45 = 5.94, and the UK counts 13.5 x 750 ÷ 1,000 = 10.1 units. The NHS lists this bottle as 10 units and the Australian Government standard drinks guide as 8, so the method matches both governments.
The grams from step 3 also feed the Widmark formula, which divides them by body weight times a body water factor, r.
What labels must show in Australia and NZ
Under Food Standards Code Standard 2.7.1, Australian and New Zealand labels must state the approximate standard drinks in any drink over 0.5% ABV. New Zealand has applied it since 1 March 2016. The Australian drink is 10 g, so a label there shows 1.4 times the US count for the same bottle. Drink counts quoted beside Australia's drink driving limits by licence type are Australian drinks, not US ones.
Alcohol by volume vs proof
In the US, proof is twice the alcohol by volume, so 40% ABV is 80 proof and 50% is 100 proof. 27 CFR 30.11 writes that rule into federal law, measured at 60 °F.
A 1.5 oz shot at 100 proof holds 17.5 g, or 1.25 US standard drinks, and a 100 proof fifth about 21.1.
Why a bar drink is often more than one
Bar pours often hold more than one standard drink. A study of 80 bars and restaurants in 10 Northern California counties bought drinks and measured them. Wine pours held 43% more alcohol than a standard drink on average, draught beer 22% more and mixed drinks 42% more. Shots and bottled beer were about even.
Against the study's 18 mL standard, that is about 20 g for wine, 17 g for draught beer and 20 g for a mixed drink. Those figures come from one region and were published in 2008. NIAAA itself counts a cocktail as "1 or more" drinks.
Any BAC worked out from drink counts is an estimate, and a 20 g pour logged as one drink makes it read low. A BAC chart by weight assumes 14 g drinks, as do answers to how many drinks reach 0.08% BAC, so a pour 43% over standard counts as about 1.4.
FAQ
How much alcohol is in vodka?
Vodka at 40% ABV (80 proof) holds 14 g of alcohol per 1.5 oz shot, one US standard drink. A 750 mL bottle holds about 237 g, which NIAAA rounds to 17 drinks.
Does alcohol by volume mean the whole bottle?
ABV is a share, not an amount. A 12% wine has 12 mL of ethanol in every 100 mL, glass or bottle. Total alcohol grows with volume, so 5 oz of 12% wine holds 14 g and the full 750 mL bottle 71 g.
Is 1 oz of liquor a standard drink?
No. One ounce of 40% spirits holds about 9.3 g of alcohol, two thirds of a US standard drink. One ounce at 100 proof holds 11.7 g, still under 14 g. At 40%, it takes the full 1.5 oz pour to make one drink.
Is a can of hard seltzer one standard drink?
Only at the right size and strength. NIAAA counts 8 to 10 oz of a malt beverage at about 7% as one. A 12 oz can at 7% holds 19.6 g, about 1.4 US drinks, while a 12 oz can at 5% holds one.
Is one beer one standard drink?
Only if it is 12 oz at 5% ABV. NIAAA counts a 16 oz pint at 5% as 1 1/3 drinks, and a 10% craft beer in a 12 oz can as two. A 12 oz light beer at about 4.2% holds 11.8 g, about 0.84 of a drink.
Conclusion
The mL and ABV on a label, plus your country's gram size, give a true drink count. A craft beer, a big wine pour or a 100 proof shot can each pass one, since the standard drink size is a measure, not a serving. Once a count becomes a BAC, what each BAC level means gives the effects, with 0.08% equal to 80 mg per 100 mL.
