BAC Calculator
Estimate blood alcohol concentration (educational).
Result
Results are estimates for general information only and are not professional advice.
Blood alcohol concentration
This tool estimates BAC with the Widmark formula for educational purposes only. Many factors affect real BAC, and it should never be used to decide whether it is safe to drive — never drink and drive.
Frequently Asked Questions
What is the BAC Calculator?
Estimate blood alcohol concentration (educational). It runs instantly in your browser and is completely free to use.
What do I need to enter to use the BAC Calculator?
The BAC Calculator asks for the following values (4): Gender, Weight (kg), Standard drinks, Hours since first drink. Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the BAC Calculator?
The BAC Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the BAC Calculator free, and do I need an account?
Yes. The BAC Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.