How blood alcohol content (bac) estimator works
Enter your body weight and sex, then list each drink with its volume (in milliliters or ounces) and ABV (alcohol by volume, as a percent). The tool converts each drink to grams of pure alcohol using ethanol's density (0.789 g/mL) and adds them up.
The estimate uses the Widmark formula: BAC (%) = (alcohol grams ÷ (body weight in grams × a sex factor)) × 100. The sex factor is roughly 0.68 for males and 0.55 for females, reflecting average body water. The result is the theoretical peak BAC if all the alcohol were absorbed at once.
Because the body metabolizes alcohol at about 0.015 %BAC per hour, the tool subtracts that amount for every hour since your first drink and clamps the result at zero. This is only an informational estimate — actual BAC varies with metabolism, food, health, medication, and many other factors, so never use it to decide if it is safe to drive.