A fifth of 80-proof liquor contains about 17 standard drinks. That number climbs to roughly 22 if the bottle is 100-proof. The answer depends entirely on the alcohol content of what’s inside, but since most common spirits (vodka, whiskey, rum, gin) are sold at 80 proof, 17 is the number most people are looking for.
What “a Fifth” Actually Means
A fifth refers to a 750 mL bottle of liquor, which is about 25.4 fluid ounces. The name dates back to when liquor was sold in bottles sized as one-fifth of a gallon. Today, 750 mL is the standard bottle you’ll find on most store shelves.
How the Math Works
In the United States, one standard drink contains 0.6 fluid ounces (14 grams) of pure alcohol. That’s the baseline the CDC and the National Institute on Alcohol Abuse and Alcoholism use for all drinking guidelines.
An 80-proof spirit is 40% alcohol by volume. A 750 mL bottle at 40% ABV holds 300 mL of pure alcohol, which works out to about 10.1 fluid ounces of pure alcohol. Divide that by 0.6 ounces per standard drink and you get roughly 17 standard drinks.
At 100 proof (50% ABV), the same 750 mL bottle holds 375 mL of pure alcohol, bumping the count to about 22 standard drinks. Some overproof rums and cask-strength whiskeys push even higher. If you want a quick rule: take the proof, recognize it changes the drink count significantly, and do the math based on the ABV listed on the label.
A Shot Is Not Always a Standard Drink
A typical shot glass holds 1.5 fluid ounces, which happens to line up almost exactly with one standard drink of 80-proof liquor. So for standard spirits, one shot equals one standard drink, and a 750 mL bottle holds about 17 shots.
That neat alignment breaks down quickly, though. A 1.5-ounce pour of 100-proof whiskey is closer to 1.3 standard drinks. A generous “double” at a bar could be 2.5 to 3 standard drinks depending on the spirit. Mixed drinks at restaurants often contain more than one shot, meaning a single cocktail can easily represent two or more standard drinks without looking like it.
How a Fifth Compares to Other Bottle Sizes
- Pint (375 mL): About 8.5 standard drinks at 80 proof
- Fifth (750 mL): About 17 standard drinks at 80 proof
- Liter (1,000 mL): About 22 standard drinks at 80 proof
- Handle (1.75 L): About 40 standard drinks at 80 proof
At 100 proof, a handle jumps to roughly 59 standard drinks. The difference between 80 and 100 proof is not a small adjustment; it can nearly double the alcohol you’re consuming from the same volume of liquid.
Why the Number Matters
Knowing there are 17 standard drinks in a fifth puts consumption into perspective. The CDC defines moderate drinking as two drinks or fewer per day for men and one drink or fewer per day for women. By that measure, a single fifth contains more than a full week’s worth of moderate drinking for men and over two weeks’ worth for women.
Binge drinking is defined as four or more drinks on one occasion for women and five or more for men. A fifth holds roughly three to four times that threshold in a single bottle. Finishing even a third of a fifth in one sitting would meet the definition of binge drinking for most people.
These numbers are useful for pacing yourself, understanding what you’ve actually consumed at a party, or simply making sense of the guidelines you see on public health websites. A “couple of drinks” from a bottle you’re sharing with friends adds up faster than most people assume, especially if the pours are generous or the proof is higher than the standard 80.