Estimate blood alcohol content over time using the Widmark formula.
The Widmark formula estimates blood alcohol concentration from the amount of alcohol consumed, body weight, sex and time elapsed. The sex-specific distribution constant r accounts for different body water percentages. Alcohol is eliminated at approximately 0.015 %/hour on average. BAC is expressed as grams per 100 mL of blood (g/dL), so 0.08 % = 0.08 g/dL.
Widmark formula
BAC = (A × 5.14) / (W × r) − 0.015 × H
This BAC estimate is for educational purposes only. Do not use it to determine whether it is safe or legal to drive. Individual elimination rates vary widely. The only reliable way to measure BAC is with a breathalyser or blood test. Never drink and drive.
One US standard drink contains 0.6 fl oz (14 g) of pure alcohol — roughly a 12 oz beer at 5 %, a 5 oz glass of wine at 12 %, or a 1.5 oz shot of 80-proof spirits.
It is an estimate. Individual elimination rates vary from about 0.010–0.020 %/hr depending on body composition, liver health, food intake and genetics. The formula is most accurate when applied on an empty stomach; food significantly slows absorption.
Yes. Alcohol distributes through body water, not fat. People with higher muscle-to-fat ratios have more body water and therefore lower peak BAC for the same amount of alcohol.