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BAC Calculator - Blood Alcohol Content

Free BAC calculator. Estimate your blood alcohol content based on drinks, weight, gender, and time. For educational purposes only.

BAC Calculator

Estimate blood alcohol content

1 drink = 12oz beer, 5oz wine, or 1.5oz spirits.

Enter your weight in pounds.

Time since you started drinking.

Estimated BAC

Enter your values to see results

and click the "Calculate" button

Blood Alcohol Content Calculator

Estimate your BAC based on the Widmark formula. This is for EDUCATIONAL PURPOSES ONLY. Never drive after drinking - even legal BAC levels impair driving.

Widmark Formula

BAC = (Drinks × 0.6) / (Weight × r) - (0.015 × Hours)

r = 0.73 for males, 0.66 for females. Legal limit: 0.08% in most US states.

Frequently Asked Questions

What is the legal BAC limit?
In most US states, 0.08% is the legal limit for drivers 21+. Commercial drivers: 0.04%. Under 21: 0.00-0.02% depending on state.
How accurate is this calculator?
This is an ESTIMATE only. Actual BAC varies based on metabolism, food, medications, and other factors. Never use this to decide if you can drive.

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