EtG Alcohol / BAC Estimator

kg
Health

The EtG / BAC Estimator uses the Widmark formula to estimate peak blood alcohol concentration from drinks, body weight, and sex, and gives a rough EtG urine detection window. For education only.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.

Formula

BAC% = (grams alcohol ÷ (weight_g × r)) × 100 − 0.015 × hours
  • One standard drink ≈ 14 g of pure alcohol; r is the Widmark distribution factor.
  • EtG windows are approximate and vary with hydration, kidney function and drinking pattern.

4 drinks, 70 kg male, 2 hrs

Inputs
  • Standard Drinks: 4
  • Body Weight: 70 kg
  • Sex: 0.68
  • Hours Since Drinking: 2

56 g ÷ (70,000 × 0.68) × 100 − 0.03 ≈ 0.088% BAC; EtG detectable up to ~48 hours.

Frequently asked questions

How accurate is a BAC estimate?
The Widmark formula is a rough estimate. Actual BAC depends on food, metabolism, and timing, so never use it to decide whether to drive.