Alcohol Elimination Time Calculator (Free) - How Long Until It Leaves Your System & BAC
Free calculator for how long alcohol takes to leave your body and your blood alcohol content (BAC), based on drink type, amount and weight, plus drunkenness stages.
Guide to Drunkenness Stages (by Blood Alcohol Content)
| Blood Alcohol Content | Stage | Typical Symptoms |
|---|---|---|
| 0.02–0.04% | Euphoric stage | Mood becomes elevated and skin flushes. Judgment is not yet significantly impaired, but reaction speed is already starting to be affected |
| 0.05–0.10% | Tipsy stage | A pleasant buzz sets in, inhibitions loosen, and mood becomes cheerful. Hand movements become more active and body temperature rises |
| 0.11–0.15% | Early intoxication | Confidence grows and speaking loudly becomes more common. Self-control becomes difficult, with unsteady standing and increased irritability |
| 0.16–0.30% | Intoxication stage | Clear signs of drunkenness appear, such as repeating the same story, rapid breathing, and staggering when walking |
| 0.31–0.40% | Late-stage intoxication (severe) | A serious condition marked by an inability to stand unassisted, clouded consciousness, and difficulty understanding speech |
| 0.41%– | Coma stage | Loss of consciousness with no response even when shaken. An emergency-transport-level condition with a risk of death from respiratory depression |
What Is the Alcohol Elimination Time Calculator?
This calculator estimates your blood alcohol content (BAC) and roughly how long it will take for that alcohol to be fully metabolized, based on the type and amount of alcohol you drank, your body weight, and your sex. The math behind it is the Widmark formula, a long-standing forensic method that adjusts for how body composition affects the way alcohol distributes and dilutes in the body.
Keep in mind that the result is only a rough estimate built on an average body build and an average metabolism rate. Your liver function, overall health, whether you have eaten, and your personal tolerance can all shift the real elimination speed considerably, sometimes by a wide margin. Please do not treat a "should be sober by now" result from this tool as permission to drive.
How to Use This Calculator
- Select your sex Body water percentage differs by sex, which changes the coefficient used to estimate blood alcohol content, so this comes first.
- Enter your body weight Body weight is used to approximate the volume of body water that alcohol distributes into.
- Choose the drink type and amount Pick a preset such as beer or a canned chuhai, or switch to custom input to specify the volume and ABV yourself.
- Enter the time elapsed since you started drinking Leaving this at 0 hours shows a state close to the peak concentration right after finishing your drink.
- Check the results You will see the current estimated blood alcohol content along with a rough figure for how long it should take to fully clear.
Tips for getting more out of it
- Select "Custom input" to freely enter a volume and ABV that is not covered by the standard presets. Check the alcohol percentage printed on the label before entering it.
- If you drank multiple types of alcohol, calculate each one separately and compare the elimination times, using the slowest one to clear as your guide (this tool only calculates one drink type per input).
- Setting the elapsed time to 0 lets you check a state close to the peak concentration right after you finish drinking. Advancing the time lets you check the concentration after some metabolism has occurred.
- The "estimated time until fully metabolized" is a rough estimate based on an average metabolism rate. Since metabolism tends to slow down when you are unwell or have not eaten, be sure to leave yourself a wide safety margin.
Ways to Use This Tool
Getting a rough sense before driving the morning after
Use last night's drinking amount as a reference point for how much alcohol might still be in your system the next morning (this cannot substitute for a legal determination).
Learning your own drinking limits
Seeing how body weight and sex change the resulting concentration for the same amount of alcohol can help you avoid overdoing it.
Comparing different drinks side by side
Run separate calculations for beer, wine, or spirits to see which combination is likely to linger in your system the longest.
Reference material for alcohol education
Combined with the six-stage guide to intoxication symptoms below, this can help illustrate the relationship between drinking amount and level of intoxication.
Glossary
- Blood alcohol content (BAC)
- The percentage of alcohol present in the blood. The higher the number, the stronger the signs of intoxication tend to be.
- Widmark formula
- A forensic calculation method that estimates blood alcohol content from body weight and sex. Published by Erik Widmark in 1932.
- Pure alcohol grams
- The weight, in grams, of the actual alcohol contained in a drink. It can be roughly estimated as volume (ml) x ABV (%) x 0.8.
- Metabolism rate
- The speed at which the liver breaks down alcohol. This tool assumes an average rate of a 0.015% drop in BAC per hour.
- Drunk driving (DUI)
- Driving while breath alcohol concentration exceeds the legal limit. This is measured differently, and in different units, from the blood alcohol content shown by this tool.
Frequently Asked Questions
Side Note — The History of the Widmark Formula and "Calculating Drunkenness"
The formula for estimating blood alcohol content from body weight and the amount of alcohol consumed is based on the "Widmark formula," published in 1932 by the Swedish forensic scientist Erik Widmark. He demonstrated experimentally that the distribution of alcohol in the body is proportional to body weight, making it possible to estimate concentration while accounting for differences in body build. More than 90 years later, this formula is still used as a foundation in forensic medicine and in traffic accident reconstruction calculations.
The coefficient known as "ρ (rho)" in the Widmark formula expresses the volume in which alcohol is diluted in the body (the volume of distribution) as a ratio to body weight. For men this is on average around 68% of body weight, and for women around 55%, a difference mainly caused by differences in body fat percentage. Because fatty tissue contains relatively little of the water that carries alcohol, a higher body fat percentage means the same amount of alcohol dissolves into less water, resulting in a higher concentration.
In Japan, the widely referenced classification for expressing degree of intoxication in stages is the six-stage system (euphoric, tipsy, early intoxication, intoxication, late-stage intoxication, and coma stages) proposed by the Japan Society of Alcohol-related Health Problems (a public interest incorporated association). This classification is a standard framework commonly used in educational materials that convey drinking guidelines and in workplace alcohol education.
Interestingly, drunk-driving enforcement under Japan's Road Traffic Act is not based on blood alcohol content but on "breath alcohol concentration (milligrams per liter of breath)." This is because breath testing is non-invasive (no blood draw required) and well suited to immediate on-the-spot judgment, but because the relationship between breath concentration and blood concentration varies slightly with factors such as body temperature and breathing pattern, the two are not strictly the same scale.