Mortgage Payment Calculator

What the Mortgage Payment Calculator does

This calculator turns a purchase price, a down payment and a rate into the number you will actually pay — and every number that sits behind it. It works out your mortgage amount, adds default insurance if your down payment is under 20%, converts your quoted rate into a true periodic rate using Canadian semi-annual compounding, and produces your payment at whichever frequency you choose.

It goes further than most Canadian payment calculators in three ways. It shows the balance you will still owe at the end of your term, because that is the figure you renew and the one that decides what your next five years look like. It shows the payment you would have to qualify at under the stress test, which is usually a few hundred dollars above the payment you would actually make. And it separates the provincial sales tax on your insurance premium out of the financed amount, because that tax is due in cash on closing day and catches people out every week.

• Your payment at monthly, semi-monthly, bi-weekly, weekly or either accelerated frequency
• Your CMHC, Sagen or Canada Guaranty premium, and the provincial tax on it
• Total interest over the life of the mortgage and total of all payments
• The balance you renew at the end of your term, plus the principal and interest paid within it
• The stress-test qualifying rate and the payment lenders will test you against

The variables that move your payment most — and how lenders treat them

Four inputs do almost all the work, and lenders look at each of them differently than borrowers do.

• Down payment — the single most consequential input. Crossing 20% removes the insurance premium entirely, which on a $750,000 purchase is usually $15,000 to $25,000 of financed cost. Below 20%, Canada uses tiered minimums rather than a flat percentage: 5% on the first $500,000, 10% on the portion between $500,000 and $1,500,000, and 20% above the insured cap. Lenders treat the source of the money as seriously as the amount — savings, a documented gift and borrowed funds are not equivalent, and borrowed down payments carry a premium surcharge.
• Interest rate — a quarter point sounds small and is not. On a $600,000 mortgage over 25 years it is roughly $85 a month and tens of thousands over the amortization. Lenders quote a nominal annual rate but Canadian fixed mortgages are compounded semi-annually not in advance, which is why your effective monthly rate is slightly below rate ÷ 12. Any calculator that divides by twelve is quietly overstating your payment.
• Amortization — stretching from 25 to 30 years lowers the payment by roughly 8 to 10% and raises lifetime interest substantially. Lenders cap insured mortgages at 25 years unless you are a first-time buyer or purchasing a new build, and they qualify you on the payment, so a longer amortization genuinely increases how much you can borrow.
• Payment frequency — this changes nothing about the rate and everything about the outcome. Accelerated bi-weekly means half the monthly payment 26 times a year, which is thirteen monthly payments instead of twelve. Lenders qualify you on the monthly-equivalent figure, so choosing accelerated does not reduce what you can borrow. It simply pays the mortgage off three to four years sooner.
• Term — this is how long your rate is locked, not how long you owe. Lenders price each term separately and the penalty to break a fixed term mid-way can be very large, so the term you choose is really a decision about flexibility, not just about rate.

How Canadian mortgage payments are actually calculated

Canadian fixed-rate mortgages are compounded semi-annually, not in advance. That is a statutory disclosure convention, and it means the conversion from your quoted annual rate to the rate applied each payment period is not a simple division.

The periodic rate is i = (1 + r ÷ 2)^(2 ÷ n) − 1, where r is your nominal annual rate and n is the number of payments per year. Your payment is then P × i ÷ (1 − (1 + i)^−N), where P is the mortgage amount and N is the total number of payments. American calculators divide the annual rate by twelve, which is correct in the United States and wrong here — it inflates a Canadian payment by a few dollars a month and compounds into a meaningfully wrong total interest figure.

Variable-rate mortgages and HELOCs are different again: most Canadian lenders compound those monthly. This calculator switches the compounding basis when you change the rate type, which is why a fixed and a variable quoted at the same number do not produce the same payment.

• Periodic rate: i = (1 + r ÷ 2)^(2 ÷ n) − 1 for fixed rates, (1 + r ÷ 12)^(12 ÷ n) − 1 for variable
• Payment: P × i ÷ (1 − (1 + i)^−N)
• Balance after k payments: P(1 + i)^k − PMT × [((1 + i)^k − 1) ÷ i]
• Accelerated frequencies are derived from the monthly payment, never solved directly

How lenders use these numbers to qualify you

The outputs here map directly onto the figures an underwriter looks at when your application lands on their desk. Understanding which number does what is the difference between guessing and knowing where you stand before you apply.

• Payment amount — feeds straight into your Gross Debt Service ratio, alongside property tax, heating and half of any condo fee. Insured lending caps GDS at 39%.
• Qualifying payment — the payment recalculated at the stress-test rate, which is the greater of your contract rate plus two percentage points or the 5.25% benchmark. Lenders run your ratios on this figure, not the one you will actually pay, which is why approvals come in lower than borrowers expect.
• Total Debt Service position — your qualifying payment plus every other monthly obligation, capped at 44% on insured deals. Credit cards are usually counted at 3% of the outstanding balance regardless of what you actually pay.
• Loan-to-value — decides whether default insurance applies, which premium band you land in, and which lenders will even look at the file. It is also the number that determines pricing: insured deals are often priced below uninsured ones.
• Balance at end of term — the amount you renew. Knowing it now tells you what your renewal exposure looks like and whether the term you are choosing lines up with your plans for the property.
• Total interest — the number that makes the case for a larger down payment, a shorter amortization or an accelerated payment schedule, all of which are decisions you make once and benefit from for decades.

Using your results well

Run the calculation once with your real numbers, then run it three more times: with 20% down, with an accelerated bi-weekly frequency, and with a rate a quarter point lower. Those three comparisons will tell you more about your mortgage than any single result can.

What this calculator deliberately does not do is pretend to be an approval. Property tax, home insurance, utilities, maintenance and closing costs sit outside the payment figure, and closing costs in particular have to come from the same pot of cash as your down payment. Lender policy also varies more than most borrowers realise — debt service limits, rental income treatment and acceptable down payment sources all differ between a big bank, a monoline lender and a credit union, and that variation is precisely what a broker is for.

• Compare 5%, 10% and 20% down to see exactly what the insurance premium is costing you
• Switch to accelerated bi-weekly to see the payoff date move three to four years earlier
• Check the qualifying payment before you make an offer, not after
• Budget the provincial tax on your premium separately — it is cash, on closing day
• Note your renewal balance and diarise a rate check 120 days before your term ends