Most people eliminate 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 four to five hours to reach 0.00. But “elimination” can mean different things depending on whether you’re talking about feeling sober, passing a breathalyzer, or clearing a urine test.
The Basic Rate of Alcohol Elimination
Your liver does the vast majority of the work. An enzyme breaks ethanol into a toxic intermediate compound, and a second enzyme quickly converts that into a harmless substance your body turns into carbon dioxide and water. This process runs at a nearly constant speed: about 0.015 BAC per hour, regardless of how much you drank. For an average-sized man, that’s roughly equivalent to processing one standard drink per hour. A standard drink in the U.S. contains about 14 grams of pure alcohol, which is a 12-ounce beer, a 5-ounce glass of wine, or a 1.5-ounce shot of liquor.
The key word here is “constant.” Unlike most substances your body processes, alcohol doesn’t clear faster just because there’s more of it in your system. Your liver works at essentially the same pace whether your BAC is 0.20 or 0.04. This is why a heavy night of drinking takes so many hours to wear off completely.
Practical Timelines by Number of Drinks
Using the 0.015-per-hour rate, you can estimate how long it takes to return to zero BAC based on how much you drank. These numbers assume you’ve stopped drinking and are waiting for your body to clear what’s already in your bloodstream.
- 2 drinks: Roughly 3 to 4 hours to reach 0.00 BAC
- 4 drinks: Roughly 6 to 8 hours
- 6 drinks: Roughly 9 to 12 hours
- 8 drinks: Roughly 12 to 16 hours
- 10 drinks: Roughly 15 to 20 hours
These ranges exist because your actual BAC depends on your body weight, sex, and how quickly you consumed the drinks. A 140-pound man who has one drink can expect it to take about three hours to fully clear. A 100-pound woman processing the same single drink may reach zero in about two hours, but she’ll typically hit a higher peak BAC in the first place, which can shift the math. The point is that a long night of heavy drinking can easily mean you still have alcohol in your blood well into the next afternoon.
What Changes Your Elimination Speed
While the 0.015-per-hour figure is a reliable average, several factors push that number up or down.
Biological sex. Women generally process alcohol more slowly than men, partly because they produce less of the enzyme that begins breaking down alcohol in the stomach. This means more alcohol reaches the bloodstream intact, leading to higher BAC levels from the same number of drinks.
Body weight and composition. A larger body with more water content dilutes alcohol more effectively, resulting in a lower BAC. Someone who weighs 200 pounds will reach a lower peak BAC than someone who weighs 130 pounds after drinking the same amount.
Drinking history. Chronic heavy drinkers actually metabolize alcohol faster than light drinkers. One study found that people classified as non-drinkers eliminated alcohol at an average rate of 0.012 per hour, social drinkers at 0.015 per hour, and those with alcohol dependence at 0.030 per hour. This faster clearance happens because the liver recruits additional enzyme pathways when it’s regularly exposed to large amounts of alcohol. This is not a health advantage; it reflects liver adaptation that often comes alongside liver damage.
Liver health. A damaged or diseased liver processes alcohol more slowly. Medications that compete for the same liver enzymes can also slow things down.
Food. Eating before or during drinking slows alcohol absorption into the bloodstream, which means your BAC peaks lower. Interestingly, though, a study comparing full-stomach and empty-stomach conditions found that the total time to reach zero BAC was almost identical: about five hours in both cases. Food changes the shape of the curve, not the finish line.
Nothing Speeds Up the Process
Coffee, cold showers, exercise, drinking water, eating bread: none of these make your liver work faster. The CDC is clear that caffeine mixed with alcohol does not reduce alcohol’s effects on your body. Coffee may make you feel more alert, but your BAC stays exactly where it would be without the caffeine. The only thing that eliminates alcohol is time.
How Long Alcohol Shows Up on Tests
Even after your BAC drops to zero, traces of alcohol or its byproducts can linger in your body. Different tests have very different detection windows:
- Blood test: Up to 12 hours
- Breath test: Up to 24 hours
- Saliva test: Up to 48 hours
- Urine test: Up to 5 days (standard tests detect a metabolite that persists long after alcohol itself is gone; with excessive drinking, detection can extend to 130 hours)
- Hair test: Up to 90 days
The urine window is the one that surprises most people. Standard workplace and clinical urine tests look for a specific metabolite your body produces when processing alcohol. This byproduct can be present days after your last drink, even though you feel completely sober and would blow 0.00 on a breathalyzer. A separate biomarker that reflects overall alcohol intake can be detected in urine for up to 14 days.
Hair testing works differently entirely. Alcohol metabolites get incorporated into the hair shaft as it grows, creating a record that stretches back roughly 90 days from the root. This type of test is less common but is used in certain legal and employment situations.
How to Estimate Your Own Timeline
If you want a rough personal estimate, you need two pieces of information: your approximate peak BAC and the 0.015 per hour elimination rate. BAC calculators are widely available online and factor in your weight, sex, number of drinks, and drinking duration. Once you have your estimated peak BAC, divide it by 0.015 to get the number of hours to reach zero.
For example, if a calculator estimates your BAC at 0.12 after a night out, that’s 0.12 divided by 0.015, which equals 8 hours from the time you stopped drinking. If your last drink was at midnight, you’d reach zero around 8 a.m. at the earliest. If you’re concerned about a urine test rather than a breathalyzer, add days rather than hours to your calculation, since those metabolites persist much longer than alcohol in the blood.
Keep in mind these are estimates. Individual variation is real, and the consequences of underestimating your BAC (particularly when driving) are severe. When in doubt, add a buffer of a few extra hours to whatever the math suggests.