How long do you have to stay in a federal prison if you have a 4 year sentence and you are on good behaviour?

In a federal prison, inmates can typically earn time off their sentence for good behavior through the First Step Act, which allows for a maximum of 54 days of good time credit per year. Therefore, for a 4-year sentence, an inmate could potentially reduce their time served by about 216 days. This means they might serve approximately 3 years and 3 months if they maintain good behavior throughout their sentence. However, actual time served can vary based on individual circumstances and any additional factors affecting their case.