How to Use This Calculator
Enter the number of drinks consumed, select the drink type (or enter custom volume and ABV), your body weight, biological sex, and how many hours have passed since your first drink. The calculator uses the Widmark formula to estimate your blood alcohol content and how long until it returns to zero.
Understanding BAC Levels
A BAC of 0.08% is the legal limit for driving in all 50 US states. However, impairment begins well before that level — even at 0.02% you may experience altered mood and reduced visual function. At 0.05% you have reduced coordination and impaired judgment. There is no "safe" level of alcohol for driving.
The Widmark Formula
This calculator uses the Widmark formula, the most widely used BAC estimation method. It accounts for the amount of pure alcohol consumed, body weight, a sex-based distribution factor (0.68 for males, 0.55 for females), and a metabolism rate of approximately 0.015% per hour. Results are estimates — individual variation is significant.
What Is a Standard Drink?
In the US, a standard drink contains about 0.6 ounces of pure alcohol. This equals roughly 12 oz of regular beer (5% ABV), 5 oz of wine (12% ABV), or 1.5 oz of distilled spirits (40% ABV). Many cocktails and craft beers contain significantly more alcohol than a standard drink.