The norm is 85% of the sentence will calculate the inmate's release date. The 15% is the "good time" credit given all inmates at the beginning. They can only lose this good time by getting incidence reports where the punishment is losing good time. If the sentence is 72 months, their time should be about 61 months, or 11 months of good time.
https://www.inmateaid.com/ask-the-inmate/if-you-get-sentenced-to-6-yrs-how-many-of-those-years-will-you-have.amp#answer
Accepted Answer Date Created: April 28,2016