Alcohol Elimination Time Calculator (Blood Alcohol Content Simulator)

Estimate your blood alcohol content (BAC) and how long it takes to metabolize based on the type and amount of alcohol you drank and your body weight. Also shows a guide to drunkenness stages and warnings about drunk-driving risk the next morning.

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

Usage Tips

  • 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.

Frequently Asked Questions

Blood alcohol content is generally said to decrease by about 0.015% per hour, but there is significant individual variation depending on physical constitution, condition, liver function, and whether you have eaten, and it is not uncommon for actual metabolism to be slower than this. Please use this only as an average guideline.

Sleep itself does not speed up the metabolism of alcohol. Since the liver breaks down alcohol at a nearly constant pace, the amount metabolized is tied more directly to how many hours have passed since you finished drinking than to how long you slept.

No. This tool's calculation result is a rough estimate that assumes an average body build and metabolism rate, and due to individual variation there is a real possibility that alcohol is still present in your body. Never conclude that it is "safe because the time has passed" — never drive after drinking.

Women generally tend to have a lower proportion of body water (and a higher body fat percentage) than men, so blood alcohol content tends to rise higher even at the same body weight and amount of alcohol consumed. This tool also uses a different calculation coefficient depending on sex.

No, they are different. Drunk-driving enforcement under Japan's Road Traffic Act is based on breath alcohol concentration (mg/L), which differs in both what is measured and its unit from the blood alcohol content (%) that this tool calculates. This tool is only a rough estimate for understanding your level of intoxication and is not a legal standard.
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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.