Alcohol leaves your body at a fixed rate of about 0.015 BAC per hour, which means a single drink typically clears in one to two hours, while a night of heavier drinking can take well over 12 hours. But “in your body” depends on what you mean: alcohol itself disappears relatively quickly, while its byproducts linger in urine, hair, and other tissues for days or even months.
How Your Body Breaks Down Alcohol
The liver does the heavy lifting. An enzyme there converts alcohol into a toxic intermediate compound called acetaldehyde, a known carcinogen. A second enzyme quickly converts acetaldehyde into acetate, which is relatively harmless. Acetate then gets broken down into carbon dioxide and water throughout the rest of your body. This two-step process handles the vast majority of alcohol elimination.
The liver processes alcohol at a remarkably steady pace: about 0.015 grams per 100 milliliters of blood per hour. That number barely changes whether you’re resting, exercising, drinking coffee, or eating food after the fact. It’s essentially a fixed conveyor belt. If your blood alcohol concentration is 0.08 (the legal driving limit in the U.S.), it will take roughly five and a half hours to return to zero.
Timeline by Number of Drinks
One standard drink in the United States 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. Each one raises your BAC by roughly 0.02 to 0.03, though this varies with body size and composition.
At the standard clearance rate of 0.015 per hour, here’s a rough guide:
- 1 to 2 drinks: alcohol fully metabolized in about 2 to 4 hours
- 3 to 4 drinks: roughly 5 to 8 hours
- 5 to 6 drinks: roughly 8 to 12 hours
- Heavy drinking (8+ drinks): 12 hours or more, potentially into the next day
The half-life of alcohol in blood is four to five hours, and full elimination takes about five half-lives. That’s why, after a heavy night of drinking, Cleveland Clinic estimates it can take around 25 hours for your body to clear all the alcohol completely.
Detection Windows by Test Type
Even after you feel sober and your BAC reads zero, traces of alcohol metabolism can still be picked up by more sensitive tests. The detection window depends entirely on what’s being tested.
- Blood: Alcohol is detectable in blood for roughly 6 to 12 hours after your last drink, depending on how much you consumed.
- Breath: A breathalyzer can detect alcohol for up to 24 hours, though 12 hours is more typical for moderate drinking.
- Saliva: Oral fluid tests pick up alcohol for up to 24 hours.
- Urine (standard): A basic urine test detects alcohol for about 12 to 24 hours.
- Urine (EtG test): This more sensitive test looks for a 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 extends to 72 hours or longer.
- Hair: Hair follicle tests can reveal alcohol use for 3 to 6 months, and sometimes longer if hair hasn’t been cut.
The EtG urine test is worth knowing about specifically because it catches people off guard. You can feel completely fine, have a BAC of zero, and still test positive two or three days later.
Why Metabolism Speed Varies Between People
While the 0.015-per-hour rate is a useful average, several factors shift it meaningfully in either direction.
Body Size and Composition
Alcohol distributes through your body’s water content, not fat. A larger person with more total body water will dilute the same number of drinks across a greater volume, resulting in a lower peak BAC. This is why a 200-pound person and a 130-pound person drinking the same amount will have very different blood alcohol levels, and different clearance timelines as a result.
Biological Sex
Women generally reach higher blood alcohol concentrations than men after drinking the same amount, even at similar body weights. Men carry more body water and less body fat on average, which creates a larger distribution volume for alcohol. Interestingly, research published in Gastroenterology found that women actually clear alcohol faster per unit of lean body mass, because their liver size relative to lean mass is proportionally larger. But in practical terms, the higher peak BAC means alcohol still takes longer to fully leave a woman’s system after equivalent consumption.
Food in the Stomach
Eating before or while drinking slows the rate at which alcohol enters your bloodstream. It doesn’t change how fast your liver works, but it lowers the peak BAC you reach, which means less total processing time. Drinking on an empty stomach is one of the fastest ways to spike your blood alcohol level.
Liver Health
You might assume liver disease dramatically slows alcohol processing, but research doesn’t clearly support that. Studies comparing people with cirrhosis to those with healthy livers found that clearance rates fell within the same range of 9 to 20 mg/dL per hour for both groups. The liver has substantial reserve capacity, and even a damaged one can metabolize alcohol at near-normal speeds in many cases.
What You Can’t Do to Speed It Up
Because alcohol elimination is governed almost entirely by enzyme activity in the liver, there’s no shortcut. Coffee, cold showers, exercise, and “sweating it out” don’t increase the clearance rate. Coffee might make you feel more alert, but your BAC stays exactly the same. Your liver will process roughly one standard drink per hour regardless of what you do in the meantime.
Time is the only thing that reliably lowers your blood alcohol level. If you had four drinks and your last one was at midnight, you likely won’t be fully clear until 4 to 6 a.m. at the earliest, and could still test positive on a breathalyzer even later than that. For anyone who needs to drive, take a test, or show up to work sober, the math is straightforward: count your drinks, note when you stopped, and add roughly one to two hours per drink from that point.