BAC Calculator
Estimate your blood alcohol concentration and time until sober using the Widmark formula.
One standard drink contains approximately 14 grams of pure alcohol.
Alcohol Metabolism Estimate
What is a BAC Calculator?
A BAC (Blood Alcohol Concentration) calculator estimates the percentage of alcohol in your bloodstream based on drinks consumed, body weight, gender, and elapsed time. It uses the Widmark formula, a widely accepted method for estimating alcohol levels.
How to Use This Calculator
- Select your gender and enter your weight with the correct unit.
- Enter the number of standard drinks consumed.
- Select the drink type for reference (all are normalized to one standard drink).
- Input how many hours have passed since your first drink.
- Click Calculate to see your estimated BAC and sober time.
Frequently Asked Questions
What is the legal BAC limit in the US?
For drivers aged 21 and over, the legal limit is 0.08%. Commercial drivers have a limit of 0.04%, and there is a zero-tolerance policy for drivers under 21 in most states.
How accurate is the Widmark formula?
The Widmark formula provides a population-level estimate. Individual metabolism, food intake, medications, and hydration can all affect actual BAC.
How fast does BAC drop?
On average, BAC decreases by about 0.015% per hour. This rate varies slightly by individual but is relatively consistent for most people.
Can I speed up sobering?
No. Time is the only factor that lowers BAC. Coffee, cold showers, and exercise may make you feel more alert but do not eliminate alcohol from your blood.