Mortgage default insurance, which is commonly referred to as CMHC insurance, is mandatory in Canada for down payments between 5% (the minimum in Canada) and 19.99%. Mortgage default insurance protects lenders, in the event a borrower ever stopped making payments and defaulted on their mortgage loan. The calculator below will give you an idea of how much CMHC insurance might cost on your mortgage. Put in an asking price and a down payment amount and it will estimate your mortgage insurance premium.