BAC Calculator
Estimate your blood alcohol content based on gender, weight, number of drinks, and time elapsed.
Important Disclaimer
This calculator is for educational purposes only. It provides a rough estimate and should never be used to determine whether you are fit to drive, operate machinery, or perform any activity that requires sobriety. Actual BAC depends on many individual factors not accounted for here. When in doubt, do not drive.
1 standard drink = Beer (12 oz / 5% ABV) = ~14g of alcohol
About This Calculator
This calculator uses the Widmark formula to estimate blood alcohol content (BAC). The formula calculates BAC as:
BAC = (Drinks × 14g × 100) / (Body Weight in grams × Gender Constant) − (0.015 × Hours)
The gender constant (r) accounts for differences in body water distribution: 0.68 for males and 0.55 for females. The body metabolizes alcohol at an average rate of approximately 0.015% BAC per hour, which is subtracted based on time elapsed.
Limitations: The Widmark formula provides only a rough estimate. Actual BAC varies based on many factors including metabolism, food intake, hydration, medications, liver function, drinking speed, and individual tolerance. This tool cannot account for these variables and should not be used as a substitute for a proper breathalyzer or blood test.