Your liver clears alcohol at a fixed rate of about 0.015% BAC per hour. That means if you stop drinking at a blood alcohol concentration of 0.08% (the legal limit in most U.S. states), it will take roughly 5.5 hours to reach 0.00%. A heavier night of drinking that pushes your BAC to 0.15% would take about 10 hours to fully clear.
But “out of your system” depends on what you mean. If you’re concerned about feeling sober, that’s one timeline. If you’re worried about a drug test, the window can stretch from hours to months depending on the type of test.
How Your Liver Processes Alcohol
Your liver does about 95% of the work. An enzyme breaks ethanol into a toxic intermediate compound called acetaldehyde (a known carcinogen), which is then quickly converted into acetate, a relatively harmless substance. Acetate eventually breaks down into carbon dioxide and water, which your body eliminates through breathing and urination.
This process runs at a nearly constant speed regardless of how much you drank. At higher BAC levels, your liver operates like a conveyor belt running at full capacity: it processes alcohol at roughly 0.015% BAC per hour and cannot be rushed. Only when your BAC drops very low (below about 0.02%) does the rate start to slow down, because the system is no longer saturated.
A small amount of alcohol, roughly 5%, leaves through your breath, sweat, and urine without being processed by the liver at all. This is what a breathalyzer detects.
Estimated Clearance Times by BAC
Since the rate is essentially fixed, you can estimate your timeline with simple math. If your BAC is 0.08%, divide by 0.015 to get about 5.3 hours. Here’s how common scenarios break down:
- BAC 0.04% (1 to 2 drinks): approximately 2.5 hours
- BAC 0.08% (3 to 4 drinks): approximately 5.5 hours
- BAC 0.12% (5 to 6 drinks): approximately 8 hours
- BAC 0.15% (7 to 8 drinks): approximately 10 hours
- BAC 0.20% (9 to 10 drinks): approximately 13.5 hours
These are rough estimates. The actual number of drinks that produces a given BAC varies widely depending on your body weight, sex, how fast you drank, and whether you ate.
Why the Timeline Varies From Person to Person
The 0.015% per hour figure is an average. Several biological factors shift it in either direction.
Body composition and sex. Alcohol dissolves in water, not fat. Because women generally carry a higher proportion of body fat and less total body water than men of similar weight, they reach higher blood alcohol levels from the same number of drinks. Men also tend to have larger livers and more lean body mass, which means they eliminate alcohol slightly faster in absolute terms. The distribution factor (how much of your body weight is available to dilute alcohol) is roughly 0.7 for men and 0.6 for women at normal weight. For people with more body fat, these numbers drop further.
Age. As you get older, your proportion of lean body mass and total body water decreases while body fat increases. This means older adults reach higher blood alcohol concentrations than younger people given the same dose, even when adjusted for body weight. Whether aging also slows the liver’s processing speed is less clear, but the higher peak BAC alone means a longer time to zero.
Genetics. Some people carry enzyme variants that change how efficiently they process alcohol or its toxic byproduct, acetaldehyde. This is especially common in people of East Asian descent and explains the facial flushing reaction some experience after even small amounts of alcohol.
How Food Changes the Timeline
Eating before or during drinking is one of the few things that genuinely changes how alcohol moves through your body, though the effect is more complex than most people realize. Food slows the absorption of alcohol from your gut, which means your BAC peaks lower and later than it would on an empty stomach. A lower peak BAC means less total time to reach zero.
Food also temporarily speeds up the liver’s elimination rate. One study in the Annals of Emergency Medicine found that a high-carbohydrate meal increased the alcohol elimination rate by 86% in the two hours after eating, jumping from 21 mg/dL per hour to 39 mg/dL per hour. By four hours after the meal, though, the rate had dropped back to baseline. So eating helps, but the boost is temporary.
What Doesn’t Speed Things Up
Coffee, cold showers, exercise, and drinking water will not lower your BAC any faster. Your liver metabolizes alcohol on a fixed schedule, and nothing you do from the outside changes that rate. Coffee may make you feel more alert, but it does not reduce the amount of alcohol in your blood. You’ll be a more awake version of intoxicated, not a sober one.
Vomiting can prevent additional alcohol from being absorbed if you’ve very recently consumed it, but once alcohol is in your bloodstream, it’s there until your liver processes it.
Detection Windows for Different Tests
If your concern is passing a test rather than feeling sober, the detection window depends entirely on what’s being tested. Standard tests that look for alcohol itself have shorter windows. Newer tests that look for metabolic byproducts, the chemical residue your body creates while breaking alcohol down, can detect drinking long after the alcohol is gone.
- Blood test: up to 12 hours
- Breathalyzer: up to 24 hours
- Saliva test: up to 24 hours
- Standard urine test: up to 24 to 48 hours
- EtG urine test: up to 48 hours after a few drinks, and 72 hours or longer after heavier drinking
- Hair follicle test: up to 90 days
The EtG test deserves special attention because it’s increasingly common in court-ordered monitoring, professional licensing programs, and workplace testing. It detects a specific byproduct called ethyl glucuronide that lingers in urine far longer than alcohol itself. A few drinks on Friday night can still produce a positive EtG result on Sunday.
A Practical Way to Estimate Your Timeline
If you want a rough sense of when you’ll be at 0.00%, count your standard drinks (one 12-ounce beer, one 5-ounce glass of wine, or one 1.5-ounce shot of liquor each count as one). Your liver processes roughly one standard drink per hour. If you had four drinks between 8 p.m. and 11 p.m., your liver needs approximately four to five hours after your last drink to clear the alcohol entirely, putting you at zero sometime around 3 to 4 a.m.
This is a simplification. If you’re a smaller person, female, older, or drank on an empty stomach, add extra time. If you’re a larger male who ate a full meal, you may clear it somewhat faster. But as a baseline rule, one drink per hour of clearance time gives you a reasonable and slightly conservative estimate to work with.