[4][5] Immediately before his election to parliament in 2009, he was working as clinical research director for a medical and sporting equipment company.
[4][6] He represented New Zealand at the 1995 Pétanque World Championships in Brussels, Belgium; the team finished 36th.
[9][10] In the 2008 general election Calder contested the Manurewa electorate and was ranked 58 on the party list.
[6][11] After the resignation of list MP Richard Worth in June 2009, Calder was elected in his place.
[12][13] Calder re-contested Manurewa in 2011 and lost, but was returned for a full term as a list MP.
[15] In 2012, Calder's private member's bill banning high-powered laser pointers in a public place was introduced into parliament; it became law in July 2014 with cross-party support.