Fixed vs Variable Mortgages in Canada

The Core Difference in Plain Terms

Neither option is universally better. The right choice depends on your budget cushion, your tolerance for payment changes, how long you expect to stay in the home, and how likely you are to break the mortgage early. Understanding how each type is calculated in Canada is essential, because Canadian mortgages do not work exactly like mortgages in the United States or elsewhere.

A key Canadian distinction is compounding. Fixed-rate mortgages in Canada compound semi-annually by law under the Interest Act. In practical terms, the monthly rate is not simply the annual rate divided by twelve. It is calculated as the annual rate compounded twice a year, converted to a monthly equivalent: monthly rate equals one plus the annual rate divided by two, raised to the power of one-sixth, minus one. Variable-rate mortgages, by contrast, generally compound monthly. That difference is small in any single month, but it affects the exact payment calculation, and it is one reason you should compare lenders using the payment they quote for the same mortgage amount and amortization, rather than trying to convert rates in your head.

How a Fixed Rate Works

With a fixed rate, you agree to a rate for a term. If, for illustration, you lock in at an example rate of 5.00 percent for five years, your regular payment is calculated at that rate for the whole term, assuming you do not change your amortization or make extra payments. Your payment does not rise if market rates rise, and it does not fall if market rates fall, until your term ends and you renew.

That predictability is the main appeal. Budgeting becomes simple: you know the mortgage portion of your housing cost for years. For households with tight cash flow, a first home, or a variable income, that certainty can be worth a great deal. It also protects you from a rate shock during the term, which matters if you would struggle to absorb a payment increase of several hundred dollars a month.

The trade-offs are real. First, you give up the benefit if rates fall during your term. You are still paying the rate you locked in, unless you break the mortgage and pay a penalty. Second, breaking a fixed mortgage early can be expensive. The penalty is often the greater of three months’ interest or an interest rate differential, which compares your contract rate with the rate the lender could now get for the remaining term. When rates have fallen sharply since you locked in, that differential penalty can be large, sometimes many thousands of dollars. Always ask for a written explanation of how your lender calculates the penalty before you sign, and ask for an example.

How a Variable Rate Works

With a variable rate, your rate is usually expressed as prime rate plus or minus a discount or premium. For illustration, if prime is 6.00 percent and your discount is 0.80 percentage points, your rate is 5.20 percent. If prime rises to 6.50 percent, your rate rises to 5.70 percent. If prime falls, your rate falls too.

What happens to your payment when prime moves depends on your lender’s product. Some variable mortgages keep your regular payment fixed and adjust how much of it goes to principal versus interest. If rates rise, more of each payment goes to interest and less to principal, so your amortization stretches out. Some lenders set a trigger rate: if rates rise enough that your payment no longer covers the interest, your payment must increase. Other variable mortgages adjust your payment directly whenever prime changes, so you feel the change immediately but your amortization stays on track.

That distinction matters enormously and is often missed. Two borrowers can both have a “variable” mortgage and experience a rate rise completely differently. One sees the same payment but a longer payoff timeline; the other sees a higher payment the next month. Before choosing a variable mortgage, confirm in writing: does my payment change when prime changes, is there a trigger rate, and what happens if I reach it?

The appeal of variable is flexibility and, historically, often a lower starting rate, though that is not guaranteed. Variable mortgages also usually have a much lower prepayment penalty, typically three months’ interest, which makes them attractive if you might move, refinance, or pay the mortgage down quickly. If you expect to break the mortgage within the term, that lower penalty can outweigh a higher rate.

A Side-by-Side Illustration

Consider a clearly labeled illustration, not a market forecast. Assume a 500,000 dollar mortgage, a 25-year amortization, and no other changes. At an example fixed rate of 5.00 percent, the monthly payment would be roughly in the low 2,900 dollar range under Canadian semi-annual compounding. At an example variable rate of 4.50 percent, the payment would be somewhat lower, roughly in the high 2,700 dollar range. That monthly difference looks attractive, but it is only the starting point.

Now imagine prime rises by one percentage point during the term. The variable borrower’s rate rises by the same amount, and depending on the product, either the payment rises or the amortization lengthens. If the payment rises, the monthly advantage can disappear quickly. If the amortization lengthens, the monthly payment may look unchanged, but the borrower will owe more at renewal and pay more interest over time unless they increase payments voluntarily.

Conversely, imagine rates fall by one percentage point. The variable borrower benefits automatically, while the fixed borrower keeps paying the original rate until renewal or until they pay a penalty to break. Over a full five-year term, the cheaper option depends on the path rates actually take, not on the starting rates alone. Anyone who tells you with certainty which will be cheaper over five years is guessing, however confident they sound.

Questions to Ask Yourself Before Choosing

• Can my budget absorb a payment increase of 200 to 400 dollars a month without stress, and for how long?
• Am I likely to move, refinance, or receive a lump sum to pay down the mortgage within the next five years?
• Do I sleep better knowing my payment is fixed, even if that means paying more if rates fall?
• Does my variable product adjust my payment, my amortization, or both, and is there a trigger rate?
• How is the early-break penalty calculated for the fixed product I am considering, with a worked example?
• What is my plan at renewal if rates are higher than they are today?

Your answers point in different directions. If a payment increase would cause real hardship, or if you value certainty above all else, fixed is often the calmer choice. If you have a strong cash cushion, you might move soon, or you want the flexibility to break cheaply, variable deserves serious consideration. Many borrowers also split the difference by choosing a shorter fixed term, such as two or three years, which offers some certainty without locking in for five years, though shorter terms can carry their own pricing trade-offs.

A Practical Way to Decide

Start by comparing total cost under several scenarios, not just the first month’s payment. Ask your mortgage professional to show you the payment and the remaining balance at renewal under three illustrative paths: rates unchanged, rates one point higher, and rates one point lower. That table makes the trade-off visible. A fixed mortgage will show the same payment in all three scenarios during the term, but a different balance if you break early. A variable mortgage will show different payments or different balances depending on the product.

Also consider your broader finances. A variable mortgage pairs awkwardly with other variable debts, such as a variable-rate line of credit, because a rate rise hits everything at once. A fixed mortgage can act as a stabilizer in that situation. Conversely, if you have a large emergency fund and no other variable debt, you may be better placed to ride out variable-rate movements.

Finally, remember that the term and the amortization are different things. The term is how long your rate and conditions last, often five years. The amortization is how long it would take to pay the mortgage off if conditions never changed, often 25 years. At the end of each term you renew, and you can renegotiate rate type, lender, and sometimes amortization, subject to qualification at that time. Rules change — check the program’s official page before deciding, and confirm current details with a licensed mortgage professional before signing.

Educational content only, not financial advice. Rates, rules and program terms change — confirm current details with a licensed mortgage professional or the program’s official source before deciding.