Calmus was born in Tulsa, Oklahoma. He is one of several high school football players to reach the professional ranks from the highly successful football program at Jenks High School in Jenks, Oklahoma. There, he was a star linebacker and running back on a team ranked third in nation and helped start a run to six consecutive Oklahoma Class 6A state championships.
The Tennessee Titans selected Calmus in the third round (77th overall pick) of the 2002 NFL Draft, and he played for the Titans from 2002 to 2004. He was signed by the Indianapolis Colts for the 2005 season, but appeared in no regular season games for the Colts. Hampered by injuries throughout his professional career, he retired after the 2005 season. As of 2010 he owned a landscaping business in Franklin, Tennessee.