Why do women reach a higher blood alcohol concentration (BAC) faster than men?

Women typically have less water in their bodies and lower levels of the alcohol-metabolizing enzyme (alcohol dehydrogenase). As a result, the same drink leads to a higher blood alcohol concentration.

How does body weight affect BAC levels?

The greater the body weight, the more water there is in the body, so alcohol becomes more diluted. A lighter person will reach a higher BAC level faster after consuming the same amount.

Does eating before drinking really help?

Yes. A meal, especially a fatty one, slows down the absorption of alcohol in the stomach, causing your BAC to rise more slowly. However, it does not change the total amount of alcohol absorbed by the body.

Why does a BAC calculator need data on gender and weight?

Because gender and body weight determine the proportion of water in the body and the rate of metabolism. This makes the result precise and personalized.

Are BAC calculator algorithms accurate?

The most accurate calculators, like ours, take into account biological differences, body weight, and the rate of alcohol elimination, making the result much more reliable than simple converters.

Why Do Women Get Drunk Faster? Science of Alcohol Metabolism & Gender Differences in 2025

Learn why women feel the effects of alcohol faster. The role of body weight, enzymes, and food – the science of alcohol metabolism explained simply.

Diagram comparing alcohol metabolism in a woman and a man of different body weights

Biology and Alcohol: Why Gender and Body Weight Matter

Not everyone reacts to alcohol in the same way. How quickly signs of intoxication appear depends on biology: body composition, enzyme activity, and even what we ate beforehand. Simply put, women reach a higher blood alcohol concentration faster than men, even after drinking the same amount.

The reason? A woman's body contains, on average, 10-15% less water than a man's. And it is water that dilutes alcohol in the blood. In addition, women have lower activity of the enzyme alcohol dehydrogenase, which is responsible for breaking down alcohol in the liver. The effect: a higher BAC from the same dose.

Key Factors Affecting the Rate of Intoxication

1. Water Content in the Body

Water is the natural "diluent" for alcohol. The more water in the body, the slower the blood alcohol concentration rises. Women generally have less water in their tissues, which is why the same amount of alcohol results in a higher BAC. ELI5: It's like pouring juice into two bottles—one with a liter of water, the other with half a liter. In the smaller one, the juice will be more "concentrated."

2. Body Weight

Body weight is a key parameter in BAC calculations. A person who weighs more has a larger volume of distribution for alcohol. ELI5: Imagine pouring a glass of wine into a large jug of water (90 kg person) and a small glass (60 kg person). The concentration in the jug will be much lower.

3. Liver Enzymes

The enzyme alcohol dehydrogenase (ADH) is responsible for breaking down alcohol in the liver. In women, its activity is lower, meaning alcohol circulates in the bloodstream for longer. ELI5: It's like the difference between two factories—one operating in fast mode, the other in slow mode. The products (alcohol metabolites) are created more slowly, so the "warehouse" (the body) is under load for longer.

4. Eating Before Drinking

Food in the stomach, especially fatty food, slows the absorption of alcohol into the bloodstream. It doesn't eliminate it, but it extends the time it takes to reach peak concentration. ELI5: It's like a traffic jam on a highway—the cars (alcohol molecules) move more slowly, so traffic is calmer, even though everyone eventually reaches the destination.

5. Alcohol Elimination Rate

On average, the body eliminates 0.01–0.02% BAC per hour. This rate depends on genetics, age, activity level, and liver health. This is the parameter, included in our calculator, that is responsible for personalizing the result. ELI5: Everyone has a different "furnace"—some burn faster, others slower.

Case Study: 90 kg Man vs. 60 kg Woman

Let's assume both individuals drank 2 glasses of wine (about 300 ml, alcohol content ~12%). Let's see how this breaks down step-by-step:

Step 1: Calculate the amount of pure alcohol: 300 ml × 12% = 36 ml = 28.4 g of ethanol.
Step 2: Determine the distribution ratio (Watson's coefficient): man ~0.68, woman ~0.55.
Step 3: Calculate the estimated Blood Alcohol Concentration (BAC):
• Man (90 kg): 28.4 / (0.68 × 90) = 0.046% BAC
• Woman (60 kg): 28.4 / (0.55 × 60) = 0.086% BAC

Conclusion: The woman will reach a BAC level nearly twice as high after consuming the same amount of alcohol. When differences in metabolism are added, this effect becomes even more pronounced. You can read more about these metabolic differences in this detailed guide.

3 Myths About Differences in Alcohol Metabolism

Myth: "It's just a matter of body weight"

Fact: Body weight is very important, but biological factors—water content, enzymes, and body composition (more fat tissue = less water)—are also key.

Myth: "You just need to eat to not get drunk"

Fact: A meal slows down absorption but doesn't reduce the total amount of alcohol. You may feel more sober, but your BAC level will remain high.

Myth: "Women just can't hold their liquor"

Fact: It's not a matter of "strength" but biology. The differences arise from physiology, not mental resilience.

Frequently Asked Questions

Why do women get drunk faster?

They have less water in their bodies and lower activity of alcohol-metabolizing enzymes, which results in a higher BAC from the same amount of alcohol.

Does fatty food prevent intoxication?

It doesn't prevent it, but it slows down alcohol absorption, so its effects are milder over time.

How much does body weight affect a BAC calculator result?

Significantly. A 30 kg difference can change the result by up to half for the same amount of alcohol.

Why does the calculator ask for gender?

Because gender affects the body's biochemistry—the amount of water, enzymes, and the rate of alcohol metabolism.

Very Important Information

This article is for educational purposes and illustrates how alcohol works in the body. It does not constitute medical or legal advice. Results from BAC calculators are approximate and depend on many individual factors. The only certain way to confirm sobriety is a test with a certified breathalyzer.

Check Your Result!

It is precisely these factors—gender, weight, and drinking patterns—that our algorithm takes into account. That's why our BAC calculator doesn't guess, but simulates your metabolism. Use it to see how your body reacts to alcohol. Knowledge is the best prevention.