Canadian mortgage rates are quoted as a rate compounded twice a year. This page converts that quote to a monthly rate with i = (1 + annual rate / 2)^(1/6) − 1, then uses the standard payment formula for the number of months. When the down payment is under 20% and the price is $1,500,000 or less, the CMHC homeowner premium is added to the loan before the payment is calculated. The published bands used here are 2.80% from just over 80% loan-to-value through 85%, 3.10% through 90%, and 4.00% through 95%. An amortization longer than 25 years adds the published 0.20 point surcharge. The premium table is CMHC’s homeowner schedule for the total loan amount.
A C$600,000 home with C$120,000 down is an 80% loan of C$480,000. At 4.5% compounded semi-annually for 25 years, principal and interest is C$2,656.67 a month. Interest over 300 payments is C$317,001.05. No CMHC premium is added, because the down payment is 20%. The same home with C$60,000 down is a 90% loan. The 3.10% premium is C$16,740, the insured loan is C$556,740, and the payment is C$3,081.41 a month.
Provincial sales tax on the premium in Ontario, Quebec, and Saskatchewan is not added, and that tax cannot be rolled into the loan. Sagen and other insurers are not priced here. The federal stress test, the minimum qualifying rate, and a lender’s approval are not decided. A non-traditional down payment, which CMHC prices at 4.50% in the top band, is not assumed. This is not an RRSP, TFSA, or land-transfer-tax calculator.