It depends which Canadian dollar. The one I like to use and is the one you refer to is the 1966 silver dollar called the voyageur (36mm). Current dollars (loonies) are 26.5mm and bronze plated nickel. Two dollar coins (toonies) are 28mm and bi-metallic (alluminum-bronze in the center and nickel ring).
Roy Kueppers makes nice gaffs for them.

D'oh, I was totally thinking of the Canadian "silver" dollar.

I forgot we still use loonies and toonies.
Loonies and toonies are nice coins to use as well.

Actualy, I should have said that the 36mm Voyageur Canadian silver dollars were made between 1953 and 1967. You'll find older canadian silver dollars of the same diameter down to 1935. After 1968, they were downsized to 32mm.
Most canadian half dollars were around 27mm to 30mm I think.

Jacques, thank you for the clarification.