How long does it take your body to completely clear alcohol?

Time. On average the body namely the breakdown and consumption takes time. A person is able to metabolize 10-15 mg/dl/hr example if blood alcohol level is 100 it will take 10 to 7.5 hours.
Depends. We metabolize about a drink an hour, women less than that. So if you have a six pack over 3-4 hours, it would take at least 6 hours after you finish for your alcohol level to approach zero, but the rate varies depending on, to some extent, size, gender and experience with alcohol. Metabolic by-products of alcohol can stick around for days, and toxic effects can last even longer.