Mortgage Renewal Calculator
See your new payment, the payment shock in dollars and percent, what extending your amortization would really cost, and the date you should start shopping your renewal — 120 days before it lands.
Run your numbers
Move a slider or type a figure, then press Calculate My Renewal. Your results appear below — nothing to download and no email required.
Want this written up?
We will email you a personalised PDF with your payment, your insurance premium, your renewal balance and a year-by-year breakdown — with your name on it.
What the Mortgage Renewal Calculator does
This calculator answers the question every renewing homeowner actually has: what will my new payment be, and how much of a shock is it going to be. It calculates your new payment over your true remaining amortization — not a fresh 25 or 30 years — and shows the dollar and percentage change against what you are paying today.
It goes further than a simple payment comparison. It shows what extending your amortization back out would do to both your monthly payment and your lifetime interest, side by side. It shows what staying with your current lender's posted offer is likely costing you against a shopped market rate. And it calculates the exact date you should start shopping — 120 days before your term ends, which is when most lenders begin offering rate holds.
- Your new payment, calculated over your actual remaining amortization
- Payment shock in dollars, percent, and annual budget impact
- The balance you will still owe at the end of your new term
- Both sides of an amortization extension: the monthly relief and the extra lifetime interest
- A rate sensitivity table and your ideal start-shopping date
The key variables that move the answer — and how lenders treat them
Renewal is different from a first mortgage in one crucial way: the amortization is already partly used up, and that is exactly where borrowers most often get their own numbers wrong.
- Remaining amortization — this is not your original amortization, and using the wrong number is the single most common renewal mistake. If you started with 25 years and are five years in, you renew over 20 years remaining, not a fresh 25. A shorter remaining amortization means a higher payment for the same balance and rate than most people expect.
- New rate versus current rate — the gap between what you were paying and what you are being offered is the entire source of payment shock. Lenders set renewal offers independently of your original rate; there is no rule requiring your renewal rate to relate to your first-term rate at all.
- Lender loyalty — renewing with your current lender usually requires no re-qualification and no new stress test at the same balance and amortization, which is genuinely convenient. But convenience is not the same as the best rate: your current lender has no obligation to offer you their most competitive number, and posted renewal offers are frequently higher than what the same lender would offer a new client, or what a broker can source elsewhere.
- Amortization extension — available at renewal in a way it usually is not mid-term. Extending lowers the payment immediately, but every year added extends the period over which interest accrues, and the extra lifetime interest cost is usually larger than borrowers estimate before seeing the actual number.
How mortgage renewals are actually calculated in Canada
Your new payment uses the same Canadian semi-annual compounding formula as any other fixed mortgage: the periodic rate is derived from your new nominal rate and payment frequency, and the payment is solved against your outstanding balance over your remaining amortization in periods, not years reset to a round number.
The balance at the end of your new term is calculated by amortizing that new payment forward for the number of periods in the term, which is very often shorter than the number of periods left in the amortization — meaning you renew again with a balance still outstanding, not a paid-off mortgage.
The amortization-extension comparison recalculates the payment over the longer period at the same rate and balance, then compares total interest across the full amortization under both scenarios — the relief and the cost are two separate calculations placed side by side deliberately, because a page that shows only the lower payment without the interest trade-off is not being straight with the reader.
- New payment: P × i ÷ (1 − (1 + i)^−N), where N is the remaining amortization in periods
- Balance at end of term: solved by amortizing the new payment through the term length
- Extension scenario: same formula, larger N, same rate — compared on both payment and total interest
- Start-shopping date: renewal date minus 120 days, the typical start of a rate hold
What you get from this calculator, and how it changes your renewal conversation
A renewal offer letter from your current lender is a starting point, not a final answer. Every number this calculator produces is designed to be brought into a conversation with a broker before you sign anything, because renewal is the one moment in a mortgage's life when switching lenders costs you the least and requires no penalty.
- Payment shock — the number to budget for immediately, in both dollars and as a share of your current payment
- Balance at end of term — tells you what you are really renewing again next time, not just what you owe today
- Cost of staying — quantifies what accepting a posted offer without shopping around is likely costing you
- Start-shopping date — the practical trigger to actually act on all of the above, well before your rate hold window closes
Using your results well
Start shopping on the date this calculator gives you, not on the day your renewal letter arrives. Lenders typically offer rate holds 90 to 120 days before a term ends, and being ready with your numbers before that window opens is what lets you actually act on a lower rate rather than just noticing one existed.
What this calculator does not do is guarantee any rate — the "shopped rate" figure is illustrative, for comparison, not an offer. It also does not model switching lenders mid-term, which usually involves a prepayment penalty on your existing mortgage; that calculation belongs on the mortgage penalty and break-mortgage calculators instead.
- Confirm your actual remaining amortization from your lender or statement, not an estimate
- Use the lump-sum field to see what a penalty-free prepayment at renewal would do to your new payment
- Compare the amortization-extension numbers carefully — the lower payment is real, but so is the extra interest
- Talk to a broker before your rate hold window opens, not after you have already signed a renewal offer
Questions people ask about this calculator
Do I have to requalify for my mortgage at renewal?
Not if you stay with your current lender at the same balance and amortization — that is treated as a straight renewal, not a new application. Switching to a new lender, or taking out additional funds, generally does require qualifying again, though some straight switches at the same terms may be exempt from the stress test depending on current rules.
Why is my renewal payment higher even though rates look similar to when I signed?
Two things commonly explain it: your remaining amortization is shorter than your original term, which raises the payment on its own, and your original rate may have been a discounted introductory offer that is not directly comparable to a current posted rate. Check both before assuming the rate itself is the whole story.
Can I pay down my mortgage without a penalty at renewal?
Yes. Renewal is one of the few moments in a mortgage's life when you can make a lump-sum prepayment of any size, in addition to your annual prepayment privilege, without triggering the penalty that would normally apply mid-term. Most homeowners do not realise this window exists.
When should I start shopping for my mortgage renewal?
About 120 days before your term ends, which is roughly when most lenders begin offering rate holds. Starting earlier means you can lock in a rate hold and still watch the market before your term actually ends, rather than being forced to decide at the last minute.
Should I extend my amortization at renewal to lower my payment?
It depends on your goal. Extending genuinely lowers your monthly payment, which can matter if cash flow is tight, but it also extends the period interest accrues over and increases the total interest paid across the life of the mortgage. This calculator shows both numbers side by side so you can weigh the trade-off with your actual figures rather than a rule of thumb.
Related calculators
The number is the easy part
What decides your file is which lender reads your income the way you earn it. We publish the qualification policy for all 77 — free, and without a form.
Get notified 90 days before your renewal
Your lender contacts you at 30 days, when you have no time to shop. We reach you at 90 — early enough to lock a hold and personalize your offers.
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Send us the file and a licensed broker comes back with what is actually available — not a posted rate you may never qualify for.
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