BAC Calculator
Use the Widmark equation to estimate blood alcohol concentration from what you drank, your weight, sex and time elapsed - including an approximate time to reach zero.
Estimated BAC
0.058%
Status
Illegal to drive in most regions
Approx hours until zero
3.9 hours
How to Use the BAC Calculator
- Enter your sex, body weight and the number of standard drinks.
- Add hours since your first drink.
- Read estimated BAC, legal-status classification and time-until-zero estimate.
Formulas Used
Widmark: BAC% = (A / (r × W)) × 100 − (β × t)
A = drinks × 14 g pure alcohol | r = 0.68 (men) or 0.55 (women)
β ≈ 0.015% per hour average elimination rate
Frequently Asked Questions
Is this BAC calculator legally reliable?
No. Individual metabolism, food, drink strength and measurement error make it only a rough educational estimate. Never drive based on a calculator result.
What is a standard drink?
In the US, one standard drink contains about 14 grams of pure alcohol: a 12 oz beer at 5%, a 5 oz glass of wine at 12%, or 1.5 oz of spirits at 40%.
How fast does the body eliminate alcohol?
On average about 0.015% BAC per hour - roughly one standard drink per hour. Coffee, cold showers and food do not speed this up significantly.
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