Why do women get drunk faster?
On this page
Because alcohol spreads through the water in your body, and pound for pound women have less water than men. After the same drink at the same weight, a woman’s level goes higher. It also stays up longer, because the liver clears a fixed amount an hour.
People usually put it down to size, or to how much someone is used to drinking. Size is part of it, since women weigh less than men on average. But NIAAA says that even when a woman and a man weigh the same and drink the same amount, her level will tend to be higher.
What we’d do
Count your drinks at your own pace, not your partner’s. If you split a bottle of wine with someone bigger, you aren’t having the same night, and your drinks will still be in your blood hours after theirs are gone.
Why body water sets the level
Stir a spoon of salt into a small pot of soup and into a big one, and the small pot tastes saltier. Alcohol works the same way. It dissolves into the water in your body, so less water means a higher concentration from the same drink.
Forensic scientists put this in one number, the Widmark factor, the share of your weight that alcohol spreads through. Our engine uses the classic averages, 0.55 for a woman and 0.68 for a man, which sit inside the published values collected in a 2015 review. At the same weight, that puts a woman’s level about a quarter higher after every drink.
Then the liver can’t catch up
The liver clears about the same amount an hour whoever you are, about 15 mg per 100 mL on average, according to a 2010 review. A higher level takes longer to come down at the same pace. On our engine, with food not known:
| Same weight, 160 lb | Woman | Man |
|---|---|---|
| 1 US drink | 2.9 hours | 2.4 hours |
| 2 US drinks | 5.6 hours | 4.6 hours |
| 4 US drinks | 10.4 hours | 8.6 hours |
The same 2010 review found women’s levels fall slightly faster, which it linked to women’s livers being bigger relative to their lean mass. It isn’t enough to make up the gap.
Two people, one bottle
A 140 lb woman and a 190 lb man each drink two 6 oz glasses of 13.5% wine with dinner, finished at 8pm and 9pm. On our engine he’s mostly cleared about 12:50am. She’s at about 3:15am, so with an 11pm bedtime his drinks reach about 1.8 hours of his sleep and hers reach about 4.3.
It shows up in the heart too. In 20,968 WHOOP members, one drink more than usual, against one less, came with a sleeping heart rate 2.8 beats higher in women and 2.4 in men, and the HRV drop was bigger in women as well.
Why the lines are lower for women
NIAAA counts 4 or more drinks on any day, or 8 or more a week, as heavy drinking for women. For men it’s 5 or more a day or 15 or more a week. NIAAA also says women start to have alcohol-related problems sooner and at lower amounts than men.
Body water isn’t set by sex alone. In the 2015 review’s tables the factor falls as BMI goes up, in men and in women, so a very lean woman can have a higher one than a heavy man. The Tonight calculator uses your own weight.
When will tonight's drinks clear?
Bed at 11:00pm
Mostly cleared by 2:50am
That's about 3.8 hours of your sleep with alcohol in your blood (3.1 to 4.9 if your liver runs faster or slower).
- Restaurant pour6 oz, 13.5%, 1.35 US drinks
- Restaurant pour6 oz, 13.5%, 1.35 US drinks
REM: More REM lost. Your evening is 0.56 g of alcohol per kg of body weight.
The full clock, with the band, the same drinks two hours earlier and what your heart does.
5 sources
- National Institute on Alcohol Abuse and Alcoholism, Women and Alcohol, updated December 2025niaaa.nih.gov
- Searle J, Alcohol calculations and their uncertainty, Medicine, Science and the Law, 2015pmc.ncbi.nlm.nih.gov
- Jones AW, Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework, Forensic Science International, 2010pubmed.ncbi.nlm.nih.gov
- National Institute on Alcohol Abuse and Alcoholism, Drinking Levels and Patterns, updated January 2026niaaa.nih.gov
- Grosicki GJ and others, Real-world effects of alcohol on heart rate, sleep, and physical activity by age and sex, PLOS Digital Health, 2026 (funded by WHOOP)pubmed.ncbi.nlm.nih.gov
