bell was born on january 7, 1992, to james mainor and erika bell. he has two younger brothers, jayden(18) and justin(14). bell was raised in plainfield, new jersey but moved to orlando, florida to attend montverde academy where he was coached by kevin sutton. he was named lake county player of the year as a junior and senior. as a senior, he averaged 18.3 points and 6.3 rebounds per game to lead montverde to a 23–5 record and national ranking. the "orlando sentinel" selected bell to the first team all-area at the conclusion of his senior year. "usa today" named him a third team all-american, and ""parade"" named him a fourth team all-american. he was scout.com's no. 78-ranked player in the 2010 recruiting class.