Alcohol Metabolism Rate Calculator

About this calculator

The body eliminates alcohol at a roughly constant rate regardless of how much is in the bloodstream — a linear process rather than the exponential decay seen with most drugs — because the liver enzyme alcohol dehydrogenase becomes saturated at typical drinking levels and processes alcohol at a fixed maximum speed. This rate, first described by Erik Widmark, averages around 0.015 g/dL per hour in most adults, though it varies with liver function, body composition, sex, tolerance and genetics.

This calculation is used to estimate how long it takes to return to a sober BAC (0.00%) or below a legal driving limit from a known or estimated current blood alcohol concentration — a planning tool, not a substitute for a breathalyzer, since individual elimination rates vary and BAC estimates from drink counts are themselves imprecise. It’s commonly referenced in road-safety and alcohol-education contexts to illustrate why “sleeping it off for an hour” rarely clears a meaningfully elevated BAC.

This calculator takes your current or estimated BAC and returns the estimated hours until you reach zero, using the body’s average linear elimination rate.