Alcohol stays in your bloodstream for roughly 12 hours after your last drink in most cases. Your body clears alcohol from the blood at a fixed rate of about 0.015 BAC per hour, which means a single drink typically takes one to two hours to process, while a night of heavier drinking can keep alcohol circulating well into the next day.
How Fast Your Body Clears Alcohol
Your liver does nearly all the work. It breaks alcohol down using a two-step enzyme process: first converting it into a toxic compound called acetaldehyde, then quickly converting that into acetate, which eventually becomes carbon dioxide and water. The speed of this process is remarkably consistent. Your BAC drops by about 0.015 per hour, and there’s almost nothing you can do to speed it up. Coffee, cold showers, and exercise don’t change the rate.
To put that in practical terms: if you stop drinking at midnight with a BAC of 0.08 (the legal limit in most U.S. states), it would take roughly five and a half hours for your BAC to reach zero, putting you at about 5:30 a.m. If your BAC peaks higher, say 0.12 after several drinks, you’re looking at about eight hours before your blood is completely clear.
What Changes How Long It Lasts
While the 0.015-per-hour rate is a useful average, several factors affect how high your BAC gets in the first place and how efficiently your body processes it on the way down.
Body composition: Women generally reach higher BAC levels than men of similar weight after the same number of drinks, largely because women tend to carry a higher proportion of body fat. Since alcohol distributes through water rather than fat, less body water means a more concentrated BAC. Interestingly, when researchers account for lean body mass, women actually eliminate alcohol slightly faster per kilogram than men. But the higher peak BAC they start with often means alcohol stays in their system longer overall.
Food in your stomach: Eating a full meal before drinking makes a substantial difference. Research measuring breath alcohol levels found that people who ate a meal before drinking absorbed only about 66 to 71 percent of the alcohol compared to those who drank on an empty stomach. Fasting subjects hit a peak concentration roughly 40 percent higher than those who had eaten. So while food doesn’t speed up metabolism, it lowers the peak your BAC reaches, which means less time above zero.
Age: As you get older, circulation slows, which means less blood flows through your liver per minute. This reduces how quickly the organ can process alcohol and allows its toxic byproducts to linger longer. Older adults also tend to have less total body water, which concentrates alcohol in the blood.
Chronic heavy drinking: Long-term heavy use activates a secondary breakdown pathway in the liver. This pathway can process alcohol somewhat faster, but it generates harmful byproducts called reactive oxygen species that damage liver cells over time. So while a heavy drinker’s body may clear alcohol slightly quicker in the short term, the cumulative liver damage eventually impairs metabolism.
A Rough Timeline by Number of Drinks
These estimates assume average body weight and that you stopped drinking at a specific point. Your actual numbers will vary, but this gives a useful frame of reference.
- 1 to 2 standard drinks: BAC likely peaks around 0.02 to 0.05. Cleared from blood in roughly 1 to 3 hours.
- 3 to 4 standard drinks: BAC may reach 0.05 to 0.08. Expect 3 to 6 hours for full clearance.
- 5 to 7 standard drinks: BAC could hit 0.08 to 0.12 or higher. You’re looking at 6 to 8 hours before your blood is alcohol-free.
- 8 or more standard drinks: BAC may exceed 0.15. Full clearance could take 10 to 12 hours or more.
A “standard drink” is 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits. Many cocktails and craft beers contain significantly more alcohol than one standard drink, so it’s easy to undercount.
Detection Windows Beyond the Blood
If you’re asking this question because of a test, it helps to know that different testing methods have different windows. A standard blood test detects alcohol for up to 12 hours after your last drink. Specialized blood tests that look for alcohol byproducts (rather than alcohol itself) can detect drinking for up to 24 hours, and one type of blood marker can flag heavy drinking from the previous one to three weeks.
Breath tests, the kind used in roadside stops, typically detect alcohol within 4 to 6 hours of your last drink but can sometimes register positive for up to 24 hours. Standard urine tests pick up alcohol for about 12 hours, while more sensitive urine tests that measure metabolic byproducts can detect drinking 24 to 72 hours later. Saliva tests have a window of up to 24 hours.
The key distinction is between detecting alcohol itself versus detecting what your body turns it into. The metabolites stick around much longer than the alcohol in your blood does.
Why You Can Still Feel Impaired After It’s Gone
Your BAC can read zero and you can still feel off. Alcohol disrupts sleep architecture, dehydrates you, and irritates the stomach lining. The toxic intermediate your liver creates during metabolism, acetaldehyde, contributes to hangover symptoms even after alcohol itself has been fully processed. So “cleared from the bloodstream” and “back to normal” are two different timelines. Most people feel fully recovered 18 to 24 hours after a night of moderate to heavy drinking, well after the alcohol itself is gone.