Blood Alcohol Calculator

Estimate your blood alcohol concentration based on drinks consumed, body weight, sex, and time elapsed.

🍺 Blood Alcohol Calculator

Weight (kg)

Sex

Standard Drinks

Hours Drinking (hrs)

Results

Est. BAC0.058%

StatusImpaired

Est. Time to Sober3.9 hours

💡 How BAC Is Estimated

BAC uses the Widmark formula: BAC = (alcohol consumed in grams / (body weight × distribution factor)) − (0.015 × hours). Distribution factor: 0.68 for males, 0.55 for females. One standard drink = 14g pure alcohol.

BAC of 0.05% = mildly impaired. 0.08% = legally drunk in many countries. 0.15%+ = severely impaired. The body metabolises alcohol at roughly 0.015% per hour — this rate is fixed and cannot be sped up.

70 kg male, 3 standard drinks over 2 hours: estimated BAC ≈ 0.04%. Time to fully sober: ≈ 2.6 hours.