How much time off for good behavior do you get in federal prison?

Question: "Time off for good behavior" is a phrase that gets thrown around a lot, but what, exactly, does it mean? And how much do you get off in the federal system?

Answer: Many prisoners can get time off—that is, a reduction of their sentences—by behaving well. In the federal system, prisoners who, in the judgment of the Bureau of Prisons, have exhibited "exemplary compliance with institutional disciplinary regulations" can get up to 54 days per year off their sentences. Prisoners are eligible if they are serving a prison term of more than one year; those serving life sentences are ineligible. Earning or making progress toward a high-school diploma or the equivalent is a factor that weighs in favor of time off. (18 U.S.C. § 3624(b).)