BAC Calculator

The calculator uses the Widmark formula: BAC = (pure alcohol oz x 5.14) / (body weight lb x r) - (0.015 x hours elapsed). Pure alcohol is the drink volume times its ABV percentage. The distribution factor r is 0.66 for men and 0.55 for women, accounting for differences in average body water content.

Most states use a 0.08 percent per se limit for drivers 21 and older, while Utah uses 0.05 percent. Commercial and under-21 rules can be lower, and impairment can support an offense below a numeric limit. The calculator's status label is not a legal determination and does not account for your jurisdiction, license class, age, or actual impairment.

No. The result is a mathematical estimate, not a breathalyzer reading. Food, medications, hydration, fatigue, and individual metabolism all shift your actual BAC beyond what any formula can predict. If you have been drinking, do not drive. The only safe BAC behind the wheel is 0.00.

The calculator uses 0.015% BAC per hour as a planning assumption. Coffee, cold showers, and water do not speed alcohol elimination. Individual rates vary, so the estimated time to zero cannot tell you when you are sober, legally permitted to drive, or safe to drive. If you have been drinking, do not drive.

The bigger factor is distribution, not metabolism rate. Women typically have a lower proportion of body water, so the same amount of alcohol spreads into a smaller fluid volume and reaches a higher blood concentration. The Widmark formula reflects this with a distribution ratio of 0.55 for women versus 0.66 for men.