Breathalyzer (BAC) Calculator

Estimate your blood alcohol concentration (BAC) using the Widmark formula. For informational purposes only: never drive after drinking alcohol.

Personal Data and Consumption

Insert information to calculate the estimated blood alcohol level.

Insert the data to calculate the estimated blood alcohol level.

Come utilizzare Calcolatore BAC

Insert physical data

Select the gender and enter your weight in kg. These data are required for the Widmark formula.

Specify the drinks consumed

Enter the number of drinks, volume in ml and alcohol percentage (ABV).

Indicate elapsed time

How many hours have passed since you started drinking alcohol.

Read Results

Get estimated blood alcohol content (BAC), state, and estimated time to sober up.

Suggerimenti

  • Never drive if you have consumed alcohol, regardless of the estimated BAC. Only abstinence from consumption guarantees safety.
  • Eat before and during alcohol consumption slows absorption significantly.
  • Body eliminates approximately 0.015 g/L per hour. A standard drink (12g of alcohol) takes about 1-1.5 hours to be eliminated.

Domande frequenti

What is the Widmark formula?

BAC calculation formula by Widmark: (grams of alcohol / (weight x rate x 1000)) x 100 - (0.015 x hours). 'r' is the distribution factor: 0.68 for males, 0.55 for females.

What is the legal limit in Italy?

In Italy the legal driving limit is 0.5 g/L (0.05%). For new drivers and transport professionals, it's 0.0 g/L.

Why does BAC differ between males and females?

Women generally have lower body water content and lower enzyme levels that metabolize alcohol, leading to higher BAC at equal consumption.

Are the results accurate?

No. This is only an indicative tool. The actual BAC can vary depending on individual metabolism, food intake, hydration, and other factors. Do not use it for driving decisions.