Most people eliminate alcohol from their bloodstream at a rate of about 0.015% BAC per hour, which works out to roughly one standard drink every 60 to 90 minutes. So if you stop drinking at a BAC of 0.08% (the legal limit in most U.S. states), it takes approximately five to six hours for your blood alcohol to reach zero. A heavier night of drinking that pushes your BAC to 0.15% or higher could take ten hours or more to fully clear.
That said, the actual timeline depends on several biological factors that vary from person to person, and the math isn’t always as simple as dividing your BAC by a fixed rate.
How Your Body Processes Alcohol
Your liver does the heavy lifting. An enzyme called alcohol dehydrogenase breaks ethanol down into acetaldehyde, which is then converted into acetate and eventually into carbon dioxide and water. For a person weighing about 154 pounds (70 kg), the liver can process a maximum of roughly 8.5 grams of pure alcohol per hour. One standard drink in the U.S. contains about 14 grams of pure alcohol, so a single beer, glass of wine, or shot of liquor takes roughly 1.5 to 2 hours to fully metabolize.
Unlike most drugs, alcohol doesn’t leave your system faster as your BAC rises. Your liver works at close to a fixed pace regardless of how much alcohol is in your blood. Think of it like a toll booth that processes one car at a time: adding more cars to the line doesn’t speed up the booth. This is why “sleeping it off” takes longer than most people expect. Your liver doesn’t work faster while you sleep, and there’s no shortcut to accelerate the process. Coffee, cold showers, and exercise don’t change your clearance rate.
Typical Clearance Times by Number of Drinks
Blood alcohol metabolism ranges between 10 and 30 mg/dL per hour depending on the individual, with most healthy adults falling around 15 to 20 mg/dL per hour. Using that average, here’s a rough guide for how long it takes to return to 0.00% BAC after your last sip:
- 2 standard drinks: about 2 to 3 hours
- 4 standard drinks: about 4 to 6 hours
- 6 standard drinks: about 7 to 10 hours
- 8 standard drinks: about 10 to 13 hours
- 10+ standard drinks: 12 hours or more
These estimates assume you’ve stopped drinking and your BAC has already peaked. If you’re still actively drinking, the clock doesn’t start until your last drink is absorbed, which typically happens 30 to 60 minutes after you finish it.
Why Clearance Time Varies Between People
Liver size is the single biggest factor. A larger liver has more enzyme capacity and clears alcohol faster. This is one reason men generally eliminate alcohol at a higher rate (measured in grams per hour) than women: men tend to have greater lean body mass and larger liver volumes.
Body water also plays a major role. Alcohol distributes through your body’s water, so people with a higher proportion of body water dilute each drink more and reach a lower peak BAC. Women typically have a lower percentage of total body water than men of similar weight, which means the same number of drinks produces a higher BAC in women even before differences in metabolism come into play.
Age matters too. Older adults have less total body water and slower elimination rates, so after the same number of drinks, they reach higher blood alcohol levels that take longer to clear. A 25-year-old and a 65-year-old drinking three beers at the same pace can end up with meaningfully different BAC curves.
Genetics, liver health, and whether you take certain medications also influence clearance speed, but for most healthy adults, the 0.015% per hour estimate is a reasonable baseline.
How Food Changes the Timeline
Eating before or while you drink doesn’t speed up alcohol metabolism, but it significantly lowers how high your BAC climbs in the first place. In controlled studies, people who ate a full meal before drinking absorbed only about 66% to 71% of the alcohol that fasting drinkers absorbed. Their peak blood alcohol was roughly 30% lower compared to drinking on an empty stomach.
The reason is straightforward: food slows the emptying of your stomach, which delays alcohol’s arrival in the small intestine where most absorption happens. A lower peak BAC means less total time before you return to zero. Interestingly, a small snack doesn’t offer much protection. The meaningful difference shows up with a full meal.
Detection Windows Beyond Blood
Even after alcohol is no longer measurable in your blood, it can still show up on other tests. A standard blood alcohol test can detect alcohol for up to about 12 hours after your last drink. Breath tests have a similar window, since they’re measuring alcohol that crosses from your blood into your lungs.
Urine tests have a wider range. A basic urine screen detects alcohol for 12 to 24 hours, but a more advanced urine test that looks for metabolic byproducts (the compounds your body produces while breaking down alcohol) can detect drinking for up to 72 to 80 hours. Hair tests can reveal alcohol use over a period of months, though they’re rarely used outside of court-ordered or workplace monitoring situations.
The Morning-After Problem
One of the most practical reasons people search this question is wondering whether they’re safe to drive the morning after drinking. The math often surprises people. If you finish your last drink at midnight with a BAC of 0.12%, your blood alcohol won’t hit zero until roughly 8:00 a.m., and that’s assuming average metabolism. A slower metabolizer might still be above the legal limit at that time.
Your BAC drops in a straight line, not a curve, so you can estimate your timeline with simple arithmetic. Take your estimated peak BAC and divide by 0.015. The result is the approximate number of hours until you reach zero. If you don’t know your peak BAC, a conservative rule of thumb is to allow at least one hour per standard drink consumed, plus one additional hour as a buffer.