BAC Calculator

Blood Alcohol Concentration (BAC) measures the amount of alcohol in your bloodstream, expressed as a percentage. For example, a BAC of 0.08% means 0.08 grams of alcohol per 100 milliliters of blood. BAC affects coordination, reaction time, and judgment, which is why legal limits exist for driving and operating machinery.

This calculator uses the Widmark formula to provide an estimated BAC based on your weight, gender, number of drinks, alcohol content, and time since drinking began. However, actual BAC levels vary depending on individual factors like metabolism rate, hydration, food intake, liver function, and tolerance.

Always treat the results as an approximation—not a guarantee of safety. Even small amounts of alcohol can impair judgment and coordination. Never rely on this estimate to determine your ability to drive or perform safety-critical tasks.