血中アルコール濃度計算

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.