Estimate your blood alcohol concentration (BAC) from beers, wine and shots, body weight, sex and time since drinking, using the Widmark formula.
About this tool
Estimate blood alcohol concentration from drinks, body weight and time.
How to use BAC Calculator
- Enter your sex and body weight.
- Enter how many beers, glasses of wine and shots you drank.
- Enter the hours since your first drink and read the estimate.
Worked example
Two beers and a glass of wine over two hours for a 75 kg man gives an estimate of about 0.04%. Never use an estimate to decide whether to drive.
How fast does alcohol leave the body?
Roughly 0.015% BAC per hour on average; nothing speeds this up, including coffee or water.
Is it safe to drive under the limit?
Any alcohol impairs driving. The only safe choice is not to drink and drive.
- BAC Calculator — Estimate blood alcohol concentration from drinks, body weight and time.
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