Calhoun and Jordon Crawford each scored 12 points and Calhoun added 13 rebounds for the Falcons (7-11, 2/3 Mid-American Conference), who never trailed after Anthony Henderson's 3-pointer broke an 8-8 tie with 11:57 left in the first half.
Bowling Green scored the final nine points of the half to lead 35-22, holding Kent State (11-8, 2-3) to 27.6 percent shooting (8 of 29) in the opening 20 minutes.
The Falcons' lead never fell below seven in the second half.
Randal Holt scored 17 points to pace the Golden Flashes. His three 3-pointers gave him 202 for his career and moved him into second place on Kent State's all-time list, two ahead of Armon Gates (2003-07) and current assistant coach Eric Haut (2000-04).
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.