Mortgage Renewal Calculator — How Bad Is the Shock, and How Do You Kill It?

In Canada, your mortgage has two clocks running. The amortization is how long it takes to pay the whole thing off — usually 25 or 30 years. The term is how long your rate is locked for — usually five years. When the term ends, the mortgage doesn't; you simply renew the remaining balance onto a new rate for a new term.

A mortgage renewal calculator works out what that new payment looks like. If you signed in 2021 at something like 1.94% and you're renewing in 2026 at 4-something, the answer is uncomfortable — and it's the reason "payment shock" has entered the national vocabulary.

But the number on its own is useless. What you actually need is the set of things you can do about it, priced honestly, so you can pick. This tool gives you five, ranks them by effect, and then solves the question everyone really wants answered: what would it take to keep paying what I'm paying now?

UK readers: "renewal" is a Canadian term. Your equivalents are the switch mortgage calculator (product transfer vs remortgage) and the remortgage calculator.

This isn't a niche problem. Roughly 60% of all mortgages held at Canadian chartered banks are renewing across 2024 to 2026, with something like $400 billion of them landing in 2026 alone. Millions of households are hitting the same wall in the same window.

What happens to your payment depends almost entirely on what you're coming off:

Five-year fixed, signed 2020–2021. You locked something near 2%. Industry analysis suggests renewers in this group typically face an increase of 15% to 24% — on a $500,000 balance that's roughly $400 to $622 more every month, or up to $7,500 a year for exactly the same house.

Variable rate. You've already been absorbing the rate rises payment by payment since 2022. Your renewal is far less dramatic — often under 1%, and sometimes a small decrease as you lock into a fixed rate below your current variable.

Across all mortgage types, the average increase for 2026 renewals lands nearer 6%. The averages hide the pain, though. The pandemic-era fixed cohort is where the damage is concentrated.

The calculator prices all five against your actual numbers and marks which ones fully eliminate the increase, which ones only dent it, and which ones don't help at all. That last category matters too — there's no point extending your amortization by five years if it only saves you $80.

Your lender mails you a renewal notice with a rate on it and a signature line. It is designed to be easy. It is easy. Signing it and mailing it back is the single most common and most expensive renewal mistake Canadians make.

That rate is usually a posted or retention rate, not the sharpest number the lender can actually do — let alone the sharpest number the market can do. Lenders know that most people won't move, and they price accordingly. The gap between a renewal letter and a shopped rate is routinely 0.3% to 0.7%. On a $500,000 balance over five years, half a point is thousands of dollars.

The renewal letter is an opening offer. Treat it like one. Ask your lender to do better — often they will, once they know you've been looking — and compare against the wider market before you decide.

For years, this was the thing that kept people trapped. Renewing with your existing lender never required requalifying — but switching to a new one meant passing the mortgage stress test all over again, at a rate well above what you'd actually pay. If your income had dipped, or rates had climbed, you could fail, and you'd be stuck taking whatever your bank offered.

That changed. Since late 2024, borrowers doing a straight switch at renewal — same balance, same amortization, no new money — no longer need to requalify at the stress-test rate with the new lender.

The practical effect is enormous: the main reason to accept a bad renewal offer has gone. If you're only moving your existing mortgage to a better rate, the door to the whole market is open in a way it wasn't three years ago. Take advantage of it. For how much you could borrow if your circumstances have changed, see the mortgage affordability calculator.

This is the one that surprises people. Bank of Canada research found that roughly half of the borrowers facing a payment increase at renewal could eliminate it completely by extending their amortization by five years. Not reduce it. Eliminate it.

The mechanism is simple: you're spreading the same balance over more payments, so each payment is smaller. If you've got 20 years left and you stretch back to 25, the monthly figure drops meaningfully — often enough to absorb a two-point rate rise on its own.

Lower payment now = more interest later. You are buying cash flow with time.

The cost is real and you should look at it squarely: paying interest for five extra years on a large balance adds up to a lot of money. The calculator shows you exactly how much.

But "more expensive over 25 years" is not the same as "wrong". If the alternative is genuinely struggling each month, or defaulting, then buying breathing room is a perfectly rational trade. Just make it deliberately — and if your finances improve later, use your prepayment privileges to claw the amortization back.

There's a third option people forget: a shorter term. If you think rates are heading down, a 1, 2 or 3-year fixed lets you ride out the high-rate period and renew again sooner, without taking on variable-rate uncertainty. It typically prices a little higher than a five-year — that's the price of the option.

If your renewal date passes without a decision, most lenders roll you onto an open or posted rate — which is the worst rate they have. Don't let that happen by accident.

Here's something most calculators get wrong, and it's the reason their numbers don't match your bank's.

Under Canada's Interest Act, fixed-rate mortgages must be compounded semi-annually, not in advance — twice a year, not monthly. American and British mortgages compound monthly. Plug a Canadian mortgage into a generic calculator built on monthly compounding and you'll get a payment that's slightly, persistently wrong.

On a small balance the error is trivial. On $500,000 over 25 years it isn't, and it's exactly the kind of discrepancy that makes you wonder which number to trust when you're already anxious about the renewal letter.

This calculator uses the correct semi-annual method. Your figures will line up with your lender's.

You borrowed in 2021 at 1.94% on a five-year fixed. Your balance at maturity is $500,000 with 20 years of amortization left. Your current payment is around $2,504 a month.

The letter arrives

Your lender offers 4.59%. That takes your payment to roughly $3,146 — an increase of about $642 a month, or $7,700 a year. Same house, same family, same income. That's payment shock.

Lever 1 — shop it

Ten minutes of comparison turns up 3.94%. Payment drops to about $3,006. You just saved $140 a month — around $8,400 over the five-year term — for the cost of some phone calls. This lever is free and almost everyone skips it.

Lever 2 — extend

Take the 3.94% and stretch the amortization from 20 years back to 25. The payment falls to roughly $2,619 — now you're only $115 above where you started, instead of $642. The increase is essentially gone.

Lever 3 — add a lump sum

Put $25,000 in at maturity (penalty-free), on top of the shopped rate and the extension, and your payment lands at about $2,488 — below your old payment. The shock is not reduced. It's erased.

What it cost you

The rate shopping cost nothing. The lump sum cost $25,000 of cash — but it's not spent, it's in your house. The amortization extension is the one with a real price tag: five extra years of interest, which the calculator quantifies for you. Now you can decide whether that trade is worth it, instead of guessing.

Official sources & further reading: use the government's own FCAC mortgage calculator, read renewal rights and the Mortgage Charter at the Financial Consumer Agency of Canada, and track the Bank of Canada policy rate. Browse every tool on the mortgage calculators homepage.