This tool gives a rough estimate of blood alcohol content, or BAC, using the classic Widmark formula. It multiplies the grams of pure alcohol consumed by a distribution factor that differs by sex, divides by body weight, and then subtracts the alcohol your body has metabolised over time at roughly 0.015 percent per hour. Enter the number of standard drinks, the grams of alcohol per drink, your weight and sex, and the hours since your first drink. The estimate appears as a percentage. Real BAC varies with food, health, medication, drink strength, and individual metabolism, so this figure can be off by a wide margin and must never be used to decide whether it is safe to drive. This is general information only, not medical or legal advice. If you have been drinking, do not drive, full stop.
It uses the Widmark formula, which relates alcohol consumed, body weight and a sex based distribution factor to estimate blood alcohol content.
The body metabolises alcohol over time at roughly 0.015 percent per hour, so the estimate drops as the hours pass.
It is only an approximation and should never be used to decide whether to drive, since individual factors vary widely.
This tool gives a rough estimate of blood alcohol content, or BAC, using the classic Widmark formula. It multiplies the grams of pure alcohol consumed by a distribution factor that differs by sex, divides by body weight, and then subtracts the alcohol your body has metabolised over time at roughly 0.
Yes. Blood Alcohol Content Calculator is completely free, with no sign-up and no usage limits.
Yes. Blood Alcohol Content Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Blood Alcohol Content Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.