Kálmán was born in 1871. Kálmán's father was Albert Kossa and his mother was Paulina Schmoll. His paternal grandparents were József Kossa and Borbála Langgasser. He had two brothers named Gábor and József. He was the second oldest of the three children. He died at the age of 6 on September 7th, 1877 in Budapest.1