Amortization Schedule Calculator

What the Amortization Schedule Calculator does

This builds the complete payment-by-payment breakdown of a Canadian mortgage: how much of each payment goes to interest against principal, how the balance falls year over year, and the date the mortgage is actually cleared. Most bank calculators give you a payment figure and stop — this shows the twenty-five year story behind it.

It also models what extra payments buy. Enter a recurring extra amount, an annual lump sum, or both, and the schedule re-runs against that scenario so the interest saved and the years removed are measured against the base schedule rather than asserted.

• A full year-by-year schedule: interest, principal, cumulative interest and remaining balance
• Total interest across the whole amortization, and the total of every payment combined
• The real payoff date, which can be years earlier than the stated amortization once extras are added
• Interest and time saved by a recurring extra payment or an annual lump sum
• The crossover year, where more of each payment starts building equity than paying interest

The variables that move the answer — and how lenders treat them

A handful of inputs drive the schedule, and lenders view each through prepayment policy and risk rather than pure arithmetic.

• Amortization length — the single biggest driver of total interest. Going from 25 to 30 years lowers the payment but can add tens of thousands in interest, because the balance stays higher for longer while it keeps accruing.
• Interest rate — small changes compound enormously across a full amortization. Your lender requotes at every renewal, so this schedule assumes a rate that will not actually hold for twenty-five years.
• Payment frequency — accelerated bi-weekly or weekly is mathematically one extra monthly payment a year. Lenders do not count it against your prepayment privilege, because it is built into the payment rather than added to it.
• Extra payments — most Canadian lenders cap prepayment privileges at 10% to 20% of the original principal per year, across lump sums and payment increases. Exceeding the privilege triggers a penalty, so check your documents before committing to the figure this page shows.
• Rate type — fixed compounds semi-annually and variable monthly, so two mortgages quoted at an identical rate produce different schedules.

How this is actually calculated in Canada

The periodic rate uses the same semi-annual convention as every calculator here: i = (1 + r ÷ 2)^(2 ÷ n) − 1 for a fixed mortgage, where r is the nominal annual rate and n is payments per year. Variable mortgages compound monthly instead.

Each period the calculator applies interest to the current balance, subtracts it from the payment to isolate the principal portion, and reduces the balance: interest = balance × i, principal = payment − interest, balance −= principal. An annual lump sum is applied on the anniversary before the next period accrues, so it starts saving interest immediately rather than at year end.

The schedule stops the moment the balance reaches zero rather than running to the scheduled payment count. That is what produces an accurate payoff date when extras are involved. An American tool that divides the annual rate by twelve is subtly wrong for a Canadian fixed mortgage — small per payment, but a meaningfully different total across twenty-five years.

• Periodic rate: (1 + r ÷ 2)^(2 ÷ n) − 1 fixed, (1 + r ÷ 12)^(12 ÷ n) − 1 variable
• Each period: interest = balance × i; principal = payment − interest; balance −= principal
• Annual lump sums are applied on the anniversary, before the next period accrues interest
• Non-monthly payments are derived from the monthly payment, matching lender practice
• The schedule terminates when the balance reaches zero, which sets the payoff date shown

What lenders use these numbers for

This is a planning tool rather than a qualification one, but several outputs connect directly to how a file is underwritten.

• Payment amount — the same figure used in your GDS and TDS ratios at application. The schedule shows how it behaves over decades, not just at approval.
• Amortization length — insured mortgages under 20% down are capped at 25 years unless you qualify for the 30-year exception. If this page is showing you a 30-year schedule, confirm your file is eligible before assuming that payment is available.
• Balance over time — exactly what a lender pulls for a mortgage statement or a refinance application, and what determines your available equity at any point in the term.
• Total interest — lenders do not underwrite against it, but it is the clearest evidence for whether a shorter amortization or a disciplined extra payment is worth the tighter budget.

Using your results well

Run it once with no extras for the baseline, then add a realistic extra payment and compare. The interest-saved figure is usually the most persuasive number here, and it is worth testing a few amounts before deciding what you can sustain every period rather than for three months.

What this deliberately does not model is a rate change. It assumes today’s rate holds for the whole amortization, which will never be true — you renew every term at a new rate, and that reshapes everything after it. Treat this as the schedule under today’s rate, not a forecast of your actual payoff date.

• Compare the base schedule against a realistic extra payment before committing
• Check your prepayment privilege limit first — exceeding it triggers a penalty
• Watch the crossover year to see when payments start building more equity than interest
• Remember the schedule assumes a constant rate; your real payoff date shifts at every renewal
• Email yourself the full year-by-year table to keep with your mortgage documents