After starting his career at a small club Šmartno he moved to Slovan in 2002, a club renowned for good work with young players. In 2004 he left for his third club from Slovenian capital LjubljanaSvoboda, where he established himself as a first team player. His talent didn't go unnoticed and he subsequently joined the Slovenian first division club Domžale in the summer of 2005. In his first 2005–06 season, he made 29 league appearances for the eventual league runners up. In the following campaigns 2006–07 and 2007–08 he won back to back titles with Domžale as well as winning Slovenian Supercup in 2007 In the 2008–09 season, Kirm led the league in assists.
On 2 July 2009, he moved to Ekstraklasa champions Wisła Kraków for an undisclosed fee from Domžale and signed for five years. He immediately established himself as a regular in the team, playing in all 37 competition matches in the 2009-10 season, while Wisła finished second in the league. In the following campaign, he won the Ekstraklasa championship with Wisła Kraków and was the club's top goalscorer with 9 goals in the league.
Kirm made his debut for the national side in August 2007 in a friendly game against Montenegro in Podgorica. In his second appearance for the national team Kirm assisted for Milivoje Novakovič in a 3–0 UEFA Euro 2008 qualifying win over Luxembourg. Since then, he has become one of the most important players of the team led by Matjaž Kek. Kirm was the only player, besides Novakovič, who played in all 2010 FIFA World Cup qualification matches. He also appeared in the starting lineup in both play-off matches with Russia, after which Slovenia qualified for the final tournament. At the World Cup he played in all three group stage games.