Federal Good Time Allowances, how is it calculated?
Statutory GCT is 15%, which works out to 54 days/year. In reality, however, because of the calculation method used by the BOP which figures GCT based on full years served, not the length of sentence, it works out to 12.5%, closer to 47 days/year. The link to the calculator explains this process and will allow you to figure out the GCT to within a day or two for any sentence.
