Mortgage Refinance Calculator

Refinancing replaces your mortgage with a new one, often for a larger amount, either to get a different rate or to take cash out of your home equity. This calculator shows how much you can borrow, how much cash is left after paying off the old mortgage and the costs, and how the monthly payment changes. It is part of our refinancing and home equity guide; for the steps involved, see how to refinance a mortgage, and for cash-out refinancing in particular, see cash-out refinance in Canada.

How much you can borrow

Mortgage insurance can't lift an ordinary refinance above that limit: under the federal mortgage insurance rules, an insured high-ratio loan has to be for buying the home or for paying off an earlier uninsured low-ratio loan. The one insured refinance is for adding secondary suites: since January 15, 2025, a home you or a close relative live in can be refinanced with mortgage insurance up to 90% of its as-improved value to build additional units, up to 4 units in total, and the extra money can only pay for the construction, with no equity taken out. See secondary suite incentives.

Qualifying for the new mortgage

Lenders check that you could afford the payments at the greater of your contract rate plus 2% or 5.25%, a floor set by OSFI for uninsured mortgages and by the federal government's mortgage insurance rules (the Minister of Finance's Eligible Mortgage Loan Regulations) for insured ones. A refinance is stress-tested like a new mortgage: since November 21, 2024, OSFI exempts a stand-alone uninsured mortgage from the test only when it moves at renewal from one federally regulated lender to another with no increase in the remaining amortization and no increase in the loan amount beyond $3,000 for the costs of the move (a straight switch). See the stress test guide.

For an insured mortgage, CMHC caps your housing costs at 39% of gross income (GDS) and your housing costs plus other debt payments at 44% (TDS); lenders set their own limits for uninsured mortgages. The debt service ratio guide shows how they are calculated.

Mortgage refinance calculator

The calculator opens with example inputs; the new-rate box starts at the Bank of Canada’s figure for the rate on new uninsured fixed mortgages with terms of 5 years and over, 4.49% for July 2026. Use the rate and penalty your lenders quote you. To estimate the penalty first, use the mortgage penalty calculator.

What the calculator computes:

• Refinance limit = home value × 80%; new loan-to-value = new mortgage ÷ home value.
• Cash left = new mortgage − current balance − penalty − other costs. A negative figure is money you would need to bring.
• Monthly payments use a fixed rate compounded half-yearly: monthly rate = (1 + rate ÷ 2)^2/12 − 1, and payment = loan × monthly rate ÷ (1 − (1 + monthly rate)^−months). The current payment uses your current rate and the years left on your amortization.
• Total interest = new payment × months of the new amortization − new mortgage.

Costs to include

The Financial Consumer Agency of Canada (FCAC) lists what to check before breaking a mortgage: a prepayment penalty, administration fees, appraisal fees, reinvestment fees and a mortgage discharge fee, and whether you have to repay any cash back you received. FCAC also notes that setting up a new mortgage usually comes with fees, which some lenders will pay part or all of. Enter the penalty and the total of the other costs your lender and lawyer quote you; the calculator assumes none.

Worked example

A lower payment over a longer amortization can still mean more interest in total; the calculator’s last line shows the total for the new mortgage. Whether the savings cover the costs is the subject of the mortgage break-even guide and when to refinance.

Alternatives to a refinance

• A home equity line of credit borrows against equity without breaking the mortgage; see HELOC vs refinance.
• Lenders may allow a blend-and-extend, which blends your current rate with a new term’s rate without a prepayment penalty, though administrative fees may apply.
• Waiting until the end of your term avoids a prepayment penalty; you can then compare lenders at renewal.