The win has earned them a fifth-place match against France this Saturday.
Canada outscored New Zealand after all four quarters and never lost the lead.
Caldwell was a starter and logged 8:23 minutes of game time. He scored four tries to help bring Canada to their first tournament win.
Zak Madell led Canada with 12 tries through only 12:37 minutes of gameplay; Barney Koneferenisi led New Zealand with 18 tries.