Enter the basics
Sex, body weight, number of standard drinks and hours since your first drink.
Blood Alcohol Content Estimator
Enter sex, body weight, standard drinks and hours elapsed to see a rough estimated blood alcohol content using the Widmark formula.
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Estimated BAC
Rough estimate only. Never drive after drinking. This tool cannot tell you if you're safe to drive, and real BAC depends on many factors it can't measure — food, medication, metabolism and more.
How it works
See the estimate
Get a rough BAC percentage based on the Widmark formula.
Read the disclaimer
Remember this is a rough estimate only, not a measurement of your actual BAC.
FAQ
How is BAC estimated here?
It uses the Widmark formula: BAC% equals standard drinks times 0.6 times 5.14, divided by weight in pounds times a sex-based constant, minus 0.015 times hours elapsed, floored at zero.
What counts as a standard drink?
About 0.6 fl oz (14 grams) of pure alcohol — roughly a 12 oz beer, a 5 oz glass of wine, or a 1.5 oz shot of spirits.
Can this tell me if I'm safe to drive?
No. This tool only shows a rough number. It cannot account for food, medication, individual metabolism or many other factors, and should never be used to decide whether to drive.