The National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health estimates that alcohol is cleared at a rate of approximately one hundred milligrams per kilogram of body weight per hour.
That’s about half an ounce of pure alcohol every two hours.
So if a person ingested approximately three drinks in a half-hour period, it would take about six hours for that alcohol to leave the body.
The speed could vary widely, as much as threefold, because of the range of individual variation in factors like body weight, absorption rates and blood alcohol levels.
