What is a standard drink?
On this page
In the US, a standard drink is about 14 grams of pure alcohol. That’s 12 oz of 5% beer, 5 oz of 12% wine or 1.5 oz of 40% spirits. Most pours people really drink are bigger than that, so most real drinks count as more than one.
People count drinks the way they count anything else: one glass, one can, one round. NIAAA’s own page says the standard amounts “may not reflect customary serving sizes.” A glass of wine at a restaurant, a pint of IPA or a cocktail with a double pour each hold more than one standard drink, and nothing on the menu says so.
What we’d do
Know your pour before you count. Check the size and the % on the label or menu, and count a restaurant glass of wine as 1.35 drinks, a 16 oz IPA as almost 2 and a double as 2. NIAAA’s drinking lines, and every number on this site, are in these standard drinks.
A quick way to count any drink
Multiply the ounces by the alcohol %, then divide by 60. That gives you US standard drinks.
A 12 oz beer at 5% is 12 x 5 / 60 = 1. A 6 oz pour of 13.5% wine is 6 x 13.5 / 60 = 1.35. A 16 oz IPA at 7% is 16 x 7 / 60 = 1.9. It works because a fluid ounce of pure alcohol weighs about 23 grams, so 14 g is about 0.6 oz of pure alcohol, the same 0.6 oz NIAAA gives.
Common pours, counted
| Pour | Grams of alcohol | US drinks |
|---|---|---|
| 12 oz light beer, 4.2% | 11.8 | 0.84 |
| 12 oz beer or hard seltzer, 5% | 14 | 1 |
| 16 oz pint, 5% | 18.7 | 1.3 |
| 16 oz IPA, 7% | 26.1 | 1.9 |
| 12 oz craft beer, 10% | 28 | 2 |
| 5 oz wine, 12% | 14 | 1 |
| 6 oz wine, 13.5% | 18.9 | 1.35 |
| 9 oz wine, 13.5% | 28.4 | 2 |
| 750 mL bottle of wine, 12% | 71 | 5.1 |
| 1.5 oz spirits, 40% | 14 | 1 |
| 3 oz spirits (a double), 40% | 28 | 2 |
The grams come from size and strength: fluid ounces, times 29.6 mL, times the alcohol %, times 0.789, the weight of a mL of alcohol in grams.
The surprising ones
Light beer isn’t much lighter in alcohol. NIAAA puts many light beers at 4.2% against 5% for regular, so a light beer has about 85% of the alcohol of a regular one. A 12 oz craft beer at 10% is two standard drinks, which NIAAA uses as its own example. And a cocktail is “1 or more”, in Rethinking Drinking’s words, because it depends on how many pours of spirits went in.
What the count changes
NIAAA counts 4 or more drinks on any day or 8 or more a week as heavy drinking for women, and 5 or more a day or 15 or more a week for men. Those are standard drinks. Someone who has two big 9 oz glasses of wine every night thinks of it as 14 a week, and it’s about 28.
The alcohol alone also carries about 7 calories a gram, according to MedlinePlus, so about 100 calories in every standard drink before any carbs or sugar. The What’s in your glass tool counts any pour for you.
Real pours, in US standard drinks
12 oz beer12 oz, 5%5 oz wine5 oz, 12%A shot1.5 oz, 40%16 oz pint16 oz, 5%6 oz pour6 oz, 13.5%16 oz IPA16 oz, 7%9 oz pour9 oz, 13.5%
A bottle750 mL, 13.5%4 sources
- National Institute on Alcohol Abuse and Alcoholism, What Is A Standard Drink? Updated December 2025niaaa.nih.gov
- National Institute on Alcohol Abuse and Alcoholism, Rethinking Drinking, How Many Drinks are in Common Containers?rethinkingdrinking.niaaa.nih.gov
- National Institute on Alcohol Abuse and Alcoholism, Drinking Levels and Patterns, updated January 2026niaaa.nih.gov
- MedlinePlus, Calories in alcoholmedlineplus.gov
