Branimir Kalaica was born on 1 June 1998 in Zagreb, Croatia. He was formed at Dinamo Zagreb, progressing through the club's youth sides, before joining Benfica in 2016 and being integrated into the B team.

A central defender and defensive midfielder, he spent his entire Benfica career with the reserve side, playing regularly for Benfica B in the second tier and for the under-23s. He was registered with the first-team squad for parts of 2020/21 and 2021/22 but his competitive football in both seasons came with the B team; he did not establish himself in the senior side.

He left Benfica in 2022 and later played for Lokomotiva Zagreb in Croatia and Astana in Kazakhstan. He has represented Croatia at youth international level.

The precise start and end dates of the Benfica contract that covered these two seasons could not be confirmed from a reliable public source.