Health
BAC Calculator
Estimate your Blood Alcohol Content with the Widmark formula. Add beers, wines, or shots and set hours elapsed. Estimate only.
Your details
Add a preset or edit values below
Estimated BAC
0.011%
Sober
Approximate time until your BAC reaches zero: 0.7 hours (assuming a metabolism rate of 0.015 per hour).
Legal disclaimer
This is an estimate only. The Widmark formula does not account for food intake, medications, individual metabolism, or measurement error. Do not use this calculator to decide if you can drive. If you have been drinking, do not drive. The only safe BAC for driving is 0.00.
Frequently Asked Questions about the BAC Calculator
What formula does this calculator use?
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.
What is the US legal limit for driving?
The federal standard is 0.08% BAC for drivers 21 and older. Utah sets a stricter limit of 0.05%. Commercial drivers are held to 0.04% nationwide, and drivers under 21 face zero-tolerance laws (0.00 to 0.02%) in every state.
Can I rely on this to decide if I can drive?
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.
How fast does the body process alcohol?
The calculator uses the standard elimination rate of 0.015% BAC per hour, the average for most adults. Coffee, cold showers, and water do not accelerate this, only time lowers your BAC. The result panel shows how many hours until your estimated BAC reaches zero.
Why do men and women metabolize alcohol differently?
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.