The Widmark formula and estimated blood alcohol level
The Widmark approach estimates blood alcohol from the amount consumed and its distribution in the body. AlcoCalc uses a simplified version with modelled absorption and elimination.
How the estimated dose is calculated
A = V × ABV / 100 × 0.789; modelled dose C = A / (m × r). V is volume in ml, A is ethanol in grams, m is body weight in kg and r is the chosen distribution ratio.
The model does more than subtract over time
The calculator divides consumption into timed portions. As each portion is absorbed, it adds alcohol to a shared estimated level while subtracting elimination. The estimate cannot fall below zero.
Model parameters
r = 0.68 or 0.55; 45 minutes for absorption and 0.15‰ per hour for elimination. These are fixed model assumptions, not a personal calibration.
Limitations
The model does not directly account for body composition, food, medication or health conditions. This page documents the implementation; it does not certify the model.
Related topics
Open alcohol calculatorSources: NIAAA – Alcohol Metabolism · NIAAA – What Is a Standard Drink?