Estimate your blood alcohol concentration in per mille with the Widmark formula, based on the drink, your weight and the time elapsed.
How to use the Blood Alcohol
Pick a preset drink or enter the volume and alcohol percentage.
Enter your body weight and select your sex.
Set the hours since you started drinking to see the current estimate.
A blood alcohol calculator that estimates your level in per mille from a drink, your body weight and sex using the well-known Widmark formula, and shows roughly when you would be sober again.
The Widmark formula divides the grams of pure alcohol you drank by your body weight times a distribution factor, about 0.7 for men and 0.6 for women, which reflects how alcohol spreads through body water. The body then eliminates roughly 0.15 per mille per hour.
Pure alcohol is what counts, not the volume of the drink: a small strong spirit can contain as much alcohol as a large beer. The calculator works from the drink and its strength to estimate the grams involved.
This is a rough estimate only. Food in your stomach, how fast you drink, your metabolism, medication, hydration and individual differences all change the real value, sometimes substantially, so treat the number as a guide, not a measurement.
It exists for education and curiosity, to illustrate how weight, sex and time affect alcohol levels. It is not a legal or medical reference, and it must never be used to decide whether to drive.
The only safe amount of alcohol before driving is none. Everything is calculated in your browser.
Frequently asked questions
It uses the Widmark formula: grams of pure alcohol divided by body weight times a distribution factor (0.7 for men, 0.6 for women). About 0.15 per mille per hour is subtracted for elimination.
It is a rough estimate. Food, drinking speed, metabolism, medication and individual differences all change the real value, so treat the result as a guide only.
No. Never use a calculator to decide whether you are fit to drive. The only safe amount of alcohol before driving is none.
In Germany the general limit is 0.5 per mille, but 0.0 applies to drivers in their probation period, those under 21, and professional drivers. Limits differ by country, so check your local law.
The body eliminates only about 0.15 per mille per hour, and this cannot be sped up by coffee, food or a cold shower. Higher levels can take many hours, often into the next day.
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