BAC Calculator — Estimate Your Blood Alcohol Content
Important Safety Disclaimer
This calculator provides estimates only and should never be used to determine whether it is safe to drive. BAC varies by individual. When in doubt, do not drive. This is not medical or legal advice.
Enter your information to see your estimated BAC
Frequently Asked Questions
How is BAC calculated?
BAC is estimated using the Widmark formula, which accounts for the amount of alcohol consumed, body weight, biological sex (which affects water content), and time elapsed. The body metabolizes roughly 0.015% BAC per hour.
What BAC level is legally drunk?
In most US states, 0.08% BAC is the legal limit for driving. Utah uses 0.05%. Commercial drivers have a 0.04% limit, and drivers under 21 have a near-zero tolerance (typically 0.02%) in most states.
How long does it take to sober up?
The body processes alcohol at roughly 0.015% BAC per hour. A BAC of 0.08% would take approximately 5-6 hours to reach zero. Nothing speeds this up — not coffee, food, or cold showers.
Is this calculator accurate?
This provides an estimate based on the Widmark formula. Actual BAC varies based on many factors including food intake, medications, metabolism, and tolerance. Never use this to decide whether it is safe to drive.