Blood Alcohol Content (BAC) Calculator
Estimate approximate BAC using the Widmark formula based on drinks, weight, sex, and time.
Educational estimate only. This calculator cannot account for individual metabolism, medication, food intake, or health conditions, and should never be used to decide whether it's safe to drive. If you plan to drink, arrange a sober ride in advance.
This tool uses the Widmark formula, a standard estimation method that accounts for total alcohol consumed, body weight, a sex-based distribution ratio, and time elapsed (alcohol metabolizes at roughly 0.015% BAC per hour on average). A "standard drink" is defined as 14 grams of pure alcohol, roughly a 12 oz beer, a 5 oz glass of wine, or a 1.5 oz shot of spirits.
Why this is only an estimate
Real BAC is affected by food in the stomach, medication, liver function, hydration, and individual variation that a formula cannot capture. Two people of identical weight and sex who drink the same amount can have meaningfully different actual BAC. Never use a calculator, this one included, to judge whether you're safe to drive.