Your liver clears alcohol at a fixed rate of about 0.015% BAC per hour, which works out to roughly one standard drink every 60 to 90 minutes. That means if you stop drinking at a BAC of 0.08% (the legal limit in most U.S. states), it will take approximately five and a half hours for your blood alcohol to reach zero.
But “leaving your body” can mean different things depending on why you’re asking. If you’re wondering when you’ll be sober, the answer is measured in hours. If you’re wondering whether a test could detect that you drank, the answer could be days or even months.
Why Alcohol Clears at a Fixed Rate
Most substances leave your body faster as their concentration drops. Alcohol is different. Your liver’s primary processing enzyme becomes fully saturated after just a drink or two, which means it can only work at one speed regardless of how much alcohol is in your system. Think of it like a toll booth with a single lane: whether there are 5 cars or 50 waiting, they pass through at the same pace.
Here’s what that looks like in practice. Your liver converts alcohol into a toxic intermediate compound, which is then quickly broken down into harmless byproducts (water and carbon dioxide) that your body eliminates easily. A secondary processing system kicks in only after heavy drinking, and a small amount of alcohol leaves through your breath, sweat, and urine without being processed at all. But the bottleneck is always that main enzyme, locked at 0.015% BAC per hour.
Rough Timeline by Number of Drinks
One standard drink contains about 14 grams of pure alcohol. That’s a 12-ounce beer, a 5-ounce glass of wine, or a 1.5-ounce shot of liquor. Using the 0.015% per hour elimination rate, here’s a general estimate of how long it takes for alcohol to fully clear your blood after your last drink:
- 1 to 2 drinks: 2 to 4 hours
- 3 to 4 drinks: 5 to 8 hours
- 5 to 6 drinks: 8 to 12 hours
- 7 to 10 drinks: 12 to 18 hours
These are rough figures. Your actual BAC depends on how quickly you drank, your body weight, your body composition, and whether you ate beforehand. Two people who drink the same amount can have very different blood alcohol levels and clearance times.
What Changes Your Clearance Speed
The 0.015% per hour rate is an average across the population. Several factors push your personal rate higher or lower.
Body Composition and Sex
Alcohol dissolves in water, not fat. Because it distributes only into the watery parts of your body, people with a higher percentage of body fat reach higher blood alcohol levels from the same amount of drinking. Women typically have a lower proportion of body water than men of similar weight, so they generally reach higher BAC levels from equivalent amounts of alcohol. At the same time, research shows that women may have lower overall elimination rates (measured in grams per hour) than men, partly because of differences in lean body mass and liver size.
Age
As you get older, your lean body mass decreases and your body fat percentage increases. Total body water drops. This means older adults tend to reach higher blood alcohol concentrations than younger people even when given the same dose adjusted for body weight. The alcohol has less water to spread into, so it concentrates more in the blood.
Food
Eating before or while drinking slows the rate at which alcohol reaches your small intestine, where most absorption happens. This doesn’t just lower your peak BAC. Research from Johns Hopkins University found that consuming food while drinking increases the rate of alcohol elimination from the bloodstream by 25 to 45%. A full stomach won’t prevent intoxication, but it meaningfully changes both how drunk you get and how quickly your body clears the alcohol.
Genetics
Some people carry genetic variants that alter how efficiently their body processes alcohol’s toxic intermediate byproduct. About 30% of people with East Asian ancestry carry a variant that significantly reduces the activity of the enzyme responsible for this step. This leads to a buildup of the toxic compound, causing facial flushing, nausea, and other unpleasant effects after drinking. Research also indicates this variant reduces the overall rate of alcohol metabolism. Similar, subtler genetic differences exist in European populations and affect early-stage alcohol processing in the stomach and liver.
Detection Windows by Test Type
Even after your BAC hits zero and you feel completely sober, traces of alcohol or its byproducts can linger in your body. Different tests look for different markers, and their detection windows vary dramatically.
- Breath: A breathalyzer can detect alcohol for up to 24 hours after drinking, though 12 hours is more typical for moderate consumption.
- Blood: A blood test can pick up alcohol for up to 12 hours after your last drink.
- Standard urine test: Alcohol itself is detectable in urine for roughly 12 to 24 hours.
- EtG urine test: This more sensitive test looks for a specific metabolic byproduct rather than alcohol itself. After a few drinks, it can return a positive result for up to 48 hours. After heavier drinking, detection may extend to 72 hours or longer.
- Hair follicle: A hair test can detect alcohol consumption for up to 90 days.
The EtG test deserves special attention because it’s commonly used in legal, employment, and treatment monitoring settings. It’s sensitive enough to detect even low levels of alcohol exposure, which is why its window stretches well beyond the point where you feel sober and would pass a breathalyzer.
Why You Can’t Speed It Up
Because your liver’s main alcohol-processing enzyme works at a fixed maximum capacity, nothing you do after drinking will make it work faster. Coffee, cold showers, exercise, and “detox” drinks don’t increase your elimination rate. Coffee may make you feel more alert, but your BAC stays the same. Water and food are helpful if consumed before or during drinking, since they slow absorption and can improve elimination. But once alcohol is in your bloodstream, time is the only thing that clears it.
The practical takeaway: if you had your last drink at midnight and your BAC peaked around 0.12%, you likely won’t be at 0.00% until roughly 8:00 a.m. Many people underestimate how long this takes. A night of heavy drinking can easily leave you above the legal driving limit well into the next morning.