Fixed vs Variable Mortgage: How to Actually Decide

What actually differs between the two

A fixed-rate mortgage locks your interest rate for the entire term (commonly five years in Canada, though shorter terms exist). Your payment doesn't move even if the Bank of Canada changes its policy rate. You know your exact cost for the term, full stop.

A variable-rate mortgage is priced off your lender's prime rate, which moves when the Bank of Canada adjusts its overnight rate. Most Canadian variable mortgages come in two flavours: adjustable payments (your payment amount changes as prime changes) and fixed payments with a floating interest portion (your payment stays level, but the split between interest and principal shifts, and in a fast-rising-rate environment you can hit a 'trigger point' where the payment no longer covers all the interest). Know which type your lender offers before you sign anything.

Fixed rates are generally set based on bond market yields, while variable rates track the Bank of Canada's policy rate through prime. That's why the two can move independently of each other — a jump in bond yields can push fixed rates up while variable rates stay flat, and vice versa.

The historical trade-off (and why it's not a guarantee)

Over long stretches of Canadian history, variable rates have on average cost borrowers less than fixed rates over the life of a mortgage. That's the standard textbook finding, and it makes intuitive sense: lenders charge a premium for the certainty a fixed rate provides.

But 'on average, over decades' is cold comfort if you're the borrower who locked in a variable rate right before a sharp tightening cycle. Recent Canadian history includes periods where variable-rate holders saw their payments or amortization stretch meaningfully as the Bank of Canada raised rates aggressively. Past averages describe what happened in aggregate — they don't predict your specific five-year window.

Nobody, including bank economists, reliably calls the direction of rates over a full term. Treat any confident prediction you read — including implied ones in this article — as a guess, not a plan.

How to decide: run it through your own filters

• Payment shock tolerance: if a meaningful jump in your payment (or your amortization quietly extending) would strain your budget, a fixed rate buys you certainty you can plan around.
• Emergency cushion: variable-rate borrowers are better positioned if they have a real buffer — three to six months of expenses, or more — to absorb rate increases without missing payments or raiding long-term savings.
• How long you'll actually hold the mortgage: if you expect to sell, refinance, or renew before the term ends, check the penalty structure on each option. Fixed-rate mortgages in Canada often carry steeper prepayment penalties (frequently calculated via an interest rate differential) than variable ones, which typically charge a flatter three-months'-interest penalty. That asymmetry matters if there's a real chance you'll break the mortgage early.
• Your stage of life and income stability: a household with a single, less predictable income or upcoming major expenses (parental leave, a career change, tuition) generally benefits more from the predictability of fixed. A dual-income household with stable jobs and savings has more room to absorb variable-rate swings.
• The rate gap itself: compare the actual fixed and variable rates you're quoted at the time you're deciding, not general narratives about which one is usually cheaper. A small gap reduces the potential upside of going variable; a wide gap raises the stakes either way.

Middle-ground options worth asking about

You're not limited to an all-or-nothing choice. Many lenders offer a convertible variable-rate mortgage that lets you lock into a fixed rate partway through the term if rates start climbing or your comfort level changes — ask about the conversion terms and any fee before you sign.

Some borrowers split the difference with a hybrid mortgage, where part of the balance is fixed and part is variable. It smooths out some of the risk in exchange for giving up some of the potential savings, and it adds complexity when it's time to renew or break the mortgage.

Whatever you choose, the term length matters as much as the rate type. A shorter fixed term gives you a chance to reassess sooner; a longer one locks in certainty for longer but can carry a larger penalty if your plans change.

Before you sign anything

Get the actual numbers in writing: the rate, the payment, the penalty formula for breaking early, and — for variable mortgages — whether it's adjustable-payment or fixed-payment with a trigger point. Ask your lender or broker to walk through what happens under a couple of rate-increase scenarios, not just the current payment.

This is a personal decision that depends on your specific budget, risk tolerance, and life plans, so use this as a framework for the conversation with your lender or a mortgage broker — not a substitute for it. A qualified mortgage professional can run your actual numbers against current rates, which change regularly and should always be confirmed directly with your lender rather than relied on from any article.

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