How BAC is Calculated

Our calculator uses the Widmark Formula, the scientific standard for estimating blood alcohol concentration.

1. The Formula

The core equation is: BAC = [Alcohol (g) / (Weight (kg) × r × 10)] - (β × Hours)

  • r (Gender Constant): 0.68 for men, 0.55 for women.
  • β (Elimination Rate): Average of 0.015% per hour.

2. Variables

BAC is influenced by your body mass, biological sex, the amount of pure ethanol consumed, and the time elapsed since consumption began. Note that food intake, medication, and individual metabolism can significantly alter these results.