Blood Alcohol Content Calculator

Estimate BAC from drinks, weight, and time.

Blood Alcohol Content (BAC) Calculator

Fill in the fields below to calculate

Disclaimer: This is an estimate only. Actual BAC can vary significantly. Never drink and drive. Always use a designated driver or ride service.

1 standard drink = 14g alcohol (355mL beer, 148mL wine, 44mL spirits)

Enter your values above to see the result.

Your Results
Estimated BAC
Hours Until Sober

(BAC < 0.01%)

Professional drivers: 0.05%

General drivers: 0.08%

BAC Impairment Levels

Sober

< 0.02%

Minimal to no impairment

Impaired

0.02 - 0.08%

Reduced coordination, reaction time

Legally Drunk

> 0.08%

Illegal in most jurisdictions

1

Widmark Formula: BAC = (drinks × 14g × 5.14) / (weight_lb × r) − 0.015 × hours
Where r =

2

BAC = ( × 14 × 5.14) / ( × ) − 0.015 ×

3

Hours until sober: BAC / 0.015 = / 0.015 = hours