The typical guideline to follow is that most sentences come with built-in "good-time credits". This is normally 15% of the total. Assuming this is available to you, 85% of 120 months is 102 months. Then there is halfway house (if available) which might carve another 3-9 months off the sentence. Be mindful that the halfway house is still a form of incarceration but reserved for inmates with no conduct problems or incident reports.
https://www.inmateaid.com/ask-the-inmate/if-someone-is-convicted-to-10-years-on-a-class-c-felony-has-a-scheduled-release-date-in-2020-what-is-approximately-the-very-earliest-they-could-expect-to-be-out#answer
Accepted Answer Date Created: September 27,2015