Kálmán Marvalits started his sports career in 1919 in his hometown, with Nagykanizsa Torna Egylet (NTE). In 1922 he moved to MTK before returning to NTE in 1923-24, and from 1925-30 he was a member of the BTC. He started as a javelin thrower, but from 1921 competed only in discus and shot. He competed in both the 1924 Paris and 1928 Amsterdam Olympics. Between 1926-30 Marvalits won five consecutive Hungarian discus titles, and in 1927 he won the English AAA title in the same event, beating fellow Hungarian Kálmán Egri into second place. After finishing his active career, Marvalits worked as a coach.