Your body eliminates alcohol at a fairly steady rate of about one standard drink per hour. So if you have three drinks, it takes roughly three hours for your blood alcohol level to return to zero. But “leaving your system” means different things depending on what’s being measured: alcohol can show up on certain urine tests for up to five days after heavy drinking, and in hair for up to 90 days.
The Basic Rate of Elimination
Your liver does the heavy lifting. It breaks alcohol down in two stages: first into a toxic compound called acetaldehyde (a known carcinogen), then into acetate, which your body converts to water and carbon dioxide. The average person with a body weight around 154 pounds (70 kg) can process about 7 grams of alcohol per hour. Since a standard drink contains 14 grams of pure alcohol, that works out to roughly one drink every one to two hours.
This rate is mostly fixed. Unlike many substances, alcohol is processed at a near-constant speed regardless of how much is in your blood. If your blood alcohol concentration (BAC) is 0.08%, the legal driving limit in most U.S. states, it will take about five hours to drop to zero. A heavier night of drinking that pushes your BAC to 0.15% could take ten hours or more.
What Counts as One Drink
People consistently underestimate how much alcohol is in their glass. In the United States, one standard drink is defined as 0.6 ounces (14 grams) of pure alcohol. That equals:
- Beer: 12 ounces at 5% alcohol
- Wine: 5 ounces at 12% alcohol
- Liquor: 1.5 ounces (one shot) of 80-proof spirits
- Malt liquor: 8 ounces at 7% alcohol
A pint of craft beer at 8% ABV is closer to two standard drinks. A generous pour of wine at a restaurant can easily be seven or eight ounces, not five. If you’re trying to estimate when you’ll be clear, counting actual standard-drink equivalents matters more than counting glasses.
Detection Windows by Test Type
Alcohol itself clears your blood relatively fast, but your body leaves behind metabolic byproducts that can be detected much longer. Here’s how the detection windows break down:
- Blood: up to 12 hours
- Breath: 12 to 24 hours
- Saliva: up to 12 hours
- Standard urine test: 12 to 24 hours (up to 72 hours or more after heavy drinking)
- EtG urine test: up to 5 days
- Hair follicle: up to 90 days
The EtG test deserves special attention because it catches people off guard. It doesn’t look for alcohol itself but for ethyl glucuronide, a byproduct your liver creates when processing alcohol. At sensitive cutoff levels (100 ng/mL), it can detect heavy drinking for up to five days and any drinking within the previous two days. This is the test commonly used in court-ordered monitoring, probation programs, and some workplace screenings.
Factors That Speed Up or Slow Down Processing
While the average rate is about one drink per hour, individual variation is real. Several biological factors shift the timeline in meaningful ways.
Sex. Women reach higher blood alcohol levels than men after drinking the same amount, even at the same body weight. This happens because women typically have a lower volume of body water to dilute the alcohol. Hormonal differences also affect how the liver responds to alcohol over time.
Body weight and composition. A larger body generally has more water volume to distribute alcohol across, which lowers peak BAC. But being overweight adds a complication: excess body fat is inflammatory on its own and can make the liver more vulnerable to alcohol’s effects over time.
Drinking history. This one surprises people. Chronic heavy drinkers actually process alcohol faster than occasional drinkers, not slower. In one study, non-drinkers eliminated alcohol at an average rate of 12 mg per deciliter per hour, social drinkers at 15 mg/dL per hour, and people with alcohol dependence at 30 mg/dL per hour. The liver ramps up its enzymatic activity with repeated heavy exposure. This faster clearance is not a health advantage: it reflects liver adaptation that often precedes liver damage.
Food. Eating before or while drinking has a dramatic effect on peak BAC. In a controlled clinical trial, drinking on a full stomach (about 635 calories) reduced peak blood alcohol by nearly 68% compared to drinking on an empty stomach. Even a small 210-calorie snack cut peak BAC by about 25%. Food slows the rate at which alcohol enters your small intestine, where most absorption happens. A lower peak BAC also means less total processing time.
What Doesn’t Work
Coffee, cold showers, exercise, naps: none of these speed up alcohol metabolism. They may make you feel more alert, but your BAC drops at the same rate regardless. Your liver can only work so fast, and there is no shortcut to increase its enzymatic capacity in the moment. The only thing that actually clears alcohol from your body is time.
Legal Driving Limits
In 48 U.S. states, the legal BAC limit for driving is 0.08%. Utah sets it lower at 0.05%. For drivers under 21, most states enforce near-zero tolerance, typically 0.02% or less. Commercial license holders face a federal limit of 0.04%.
If you’re traveling, limits vary significantly. Most of Europe sets the limit at 0.05%, including Germany, France, Italy, and Spain. Sweden and Poland use 0.02%. A few countries, including Czechia, Romania, and Slovakia, enforce zero tolerance. Scotland also uses 0.05%, while England, Wales, and Northern Ireland match the U.S. standard at 0.08%.
Keep in mind that a BAC of 0.05% after a night of moderate drinking could easily persist into the next morning. If you had four or five drinks ending at midnight, you might still be above some of these thresholds at 7 or 8 a.m. Morning-after impairment is a genuine and underappreciated risk.
A Rough Timeline for Common Scenarios
These estimates assume an average-sized adult who processes about one standard drink per hour, starting from the last sip:
- 2 drinks over dinner: BAC near zero within 2 to 3 hours
- 4 drinks over 3 hours: BAC near zero within 4 to 5 hours after your last drink
- 6 drinks over 4 hours: BAC near zero within 5 to 7 hours after your last drink
- Heavy night (8+ drinks): BAC may not reach zero for 10 hours or more
These are approximations. Your actual clearance depends on your size, sex, food intake, and individual liver function. For detection on an EtG urine test, add one to five days beyond the point when your BAC hits zero. For hair testing, assume any drinking in the past three months is potentially detectable.