Amortization is simply the clock your mortgage runs on: the number of years it would take to pay the balance to zero at your current rate and payment. In Canada the standard is 25 years, and 30 years is the main alternative. Lenders love to sell the 30-year on the monthly payment. They rarely volunteer the total cost. Here is both, in dollars.
Same example throughout: a $450,000 mortgage, 5-year fixed rate at 4.64%.
That is the entire sales pitch for the 30-year in one number: $219 a month stays in your pocket. For a young family juggling daycare costs, or anyone buying near the top of what the stress test allows, that breathing room is real money every month. The question is what it costs you over time.
Stretching the identical loan over 30 years instead of 25:
Read that twice. The $219 a month you "save" costs you $73,400 over the life of the loan. Five extra years of payments means five extra years of interest compounding against a balance that shrinks more slowly. The lender is not giving you a discount; it is selling you time at full price.
Most Canadians renew every five years, so the five-year mark is where amortization quietly shows up in your net worth. After the first 5-year term:
That $14,700 is not abstract. It is part of your down payment on the next home, your room to refinance, your cushion if prices dip. Early in any mortgage, almost every dollar of your payment is interest, and the longer amortization keeps you in that interest-heavy phase for longer.
This is where Canadian rules matter. If your down payment is less than 20%, your mortgage requires default insurance, and insured mortgages are capped at 25 years, with two exceptions: first-time homebuyers and buyers of newly built homes can access insured 30-year amortizations. Put 20% or more down and the mortgage is uninsured, and most lenders will offer 30 years with no special conditions.
One more wrinkle worth knowing before renewal: extending your amortization at renewal time usually means refinancing, which means requalifying under current rules and paying legal and appraisal costs. The amortization you choose at purchase tends to stick around, so choose it deliberately.
Here is the move that gets you the best of both worlds: take the 30-year amortization for the lower required payment, then pay it like a 25-year.
The math is clean. Pay $2,537 a month, the 25-year payment, on the 30-year mortgage, an extra $219, and the loan is gone in exactly 25 years with the same $311,100 in total interest. You pay nothing extra for the flexibility. Meanwhile your contractual minimum stays at $2,318, so in a brutal month, furnace dies and car dies in the same week, you can drop to the minimum without missing a payment or calling the bank.
Two conditions. First, you have to actually make the extra payments, which means automating them on day one before lifestyle creep spends the $219. Set the payment to $2,537 from the start and treat the $2,318 minimum as an emergency valve, not the plan. Second, stay inside your prepayment privileges: most lenders let you increase payments or make lump sums worth 15 to 20% of the balance per year without penalty. An extra $219 a month is well inside that range, but confirm your own lender's terms.
When is the 30-year the wrong call? When the lower payment is what qualifies you for a house you could not afford on a 25-year schedule. Lenders qualify you on the contractual payment, so a 30-year amortization can nudge a larger mortgage through the stress test. If that larger mortgage only works because of the longer clock, you are not buying breathing room. You are buying a more expensive house with borrowed time.
On a $450,000 mortgage at 4.64%, a 30-year amortization saves $219 a month but costs about $73,400 more in interest and leaves you with roughly $14,700 less equity after five years. Take the 30 for the flexibility if you need it, pay it like a 25, and automate the extra payment before you get used to spending it.
Shopping for a mortgage or coming up on renewal? Browse the live crowdsourced rate reports on fiveyear.ca to see what Canadians are actually getting.