Blood Alcohol Content (BAC) Calculator
About the BAC Calculator
This calculator estimates your Blood Alcohol Content (BAC) using the Widmark formula. BAC is the percentage of alcohol in your bloodstream and is used to assess intoxication levels. Individual metabolism, food intake, and other factors can affect actual BAC.
The Formula
Widmark formula: BAC = [(A × 5.14) / (W × r)] − 0.015 × H, where A = total alcohol consumed in ounces (drinks × volume × ABV), W = weight in pounds, r = alcohol distribution ratio (0.73 for men, 0.66 for women), and H = hours of drinking. The 0.015 represents the average alcohol metabolism rate per hour.
Frequently Asked Questions
How quickly does the body metabolize alcohol?
The liver metabolizes alcohol at an average rate of about 0.015 BAC per hour. This rate is relatively constant and cannot be accelerated by coffee, cold showers, or exercise. Only time will lower your BAC.
What is the legal BAC limit for driving?
In most US states, the legal limit is 0.08% for drivers aged 21 and over. Commercial drivers have a limit of 0.04%. For drivers under 21, many states have zero-tolerance laws with limits of 0.01–0.02%. Always designate a sober driver.