Amortization Schedule Calculator

What the Amortization Schedule Calculator does

This calculator builds the complete payment-by-payment breakdown of a Canadian mortgage: how much of every payment goes to interest versus principal, how the balance declines year over year, and the exact date the mortgage is paid off. Most bank calculators show you a single payment number and stop there — this one shows the full 25- or 30-year story behind it.

It also models what extra payments actually buy you. Enter a recurring extra amount per period, an annual lump sum, or both, and the schedule re-runs against that scenario so you can see the interest saved and the years shaved off the payoff date, compared directly against the base schedule with no extras.

• A full year-by-year schedule: interest paid, principal paid, cumulative interest and remaining balance
• Total interest over the entire amortization, and the total of all payments combined
• The actual payoff date, which can be years earlier than the stated amortization once extra payments are added
• Interest saved and time saved from extra regular payments or an annual lump sum
• The principal-versus-interest crossover year — the point where more of your payment starts building equity than paying the bank

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

The schedule is sensitive to a handful of inputs, and lenders view each of them through the lens of risk and prepayment policy, not just arithmetic.

• Amortization length — the single biggest driver of total interest. Stretching from 25 to 30 years lowers the payment but can add tens of thousands of dollars in interest over the life of the mortgage, because the balance stays higher for longer while it continues to accrue interest.
• Interest rate — a small change compounds enormously over a 25-year schedule. Lenders requote this rate at every renewal, so the schedule you see today assumes your current rate holds for the full amortization, which it will not.
• Payment frequency — switching to accelerated bi-weekly or accelerated weekly is mathematically equivalent to making one extra monthly payment per year. Lenders do not treat this as an extra payment for privilege-limit purposes; it is baked into the payment amount itself, so it does not use up your prepayment allowance.
• Extra payments — most Canadian lenders cap prepayment privileges at 10% to 20% of the original principal balance per year, applied either to lump sums, a permanent increase to the regular payment, or both, depending on the lender. Exceeding the privilege triggers a prepayment penalty, so the extra-payment scenario here should be checked against your actual mortgage documents before you commit to it.
• Rate type — fixed and variable mortgages compound differently in Canada (semi-annually versus monthly), which means a fixed and a variable mortgage quoted at an identical rate will not produce identical schedules.

How this is actually calculated in Canada

The schedule starts from the same semi-annual compounding convention used across every calculator on this site: the periodic rate is i = (1 + r ÷ 2)^(2 ÷ n) − 1 for fixed mortgages, where r is the nominal annual rate and n is payments per year. Variable-rate mortgages compound monthly instead, i = (1 + r ÷ 12)^(12 ÷ n) − 1.

Each period the calculator applies interest to the current balance, subtracts that interest from the payment to isolate the principal portion, and reduces the balance by that amount — interest_k = balance × i, principal_k = payment − interest_k, balance_k = balance_(k−1) − principal_k. An annual lump sum is applied directly against the balance on the anniversary period, before interest is calculated for the next period, so it starts saving interest immediately rather than at the end of the year.

The schedule stops the moment the balance reaches zero rather than continuing to the scheduled number of payments — this is what produces an accurate payoff date when extra payments are involved, instead of just recomputing a new fixed payment. American amortization tools that divide the annual rate by twelve produce a schedule that is subtly wrong for a Canadian fixed mortgage; the gap is small per payment but adds up to a meaningfully different total-interest figure over 25 years.

• Periodic rate: i = (1 + r ÷ 2)^(2 ÷ n) − 1 for fixed, (1 + r ÷ 12)^(12 ÷ n) − 1 for variable
• Each period: interest = balance × i; principal = payment − interest; balance −= principal
• Annual lump sums are subtracted from the balance on the anniversary period, before that period's interest accrues
• The schedule terminates when the balance reaches zero, which drives the actual payoff date shown above

What you get, and how lenders use these numbers to qualify you

This schedule is a planning and equity-building tool rather than a qualification tool, but a couple of its outputs connect directly to how a file gets underwritten.

• Payment amount — this is the same figure used in your Gross Debt Service and Total Debt Service ratios at the time of application; the schedule shows how that payment behaves over decades, not just at the moment of approval.
• Amortization length — insured mortgages (under 20% down) are capped at 25 years unless you qualify for the 30-year exception, so if this calculator is showing you a 30-year schedule, confirm your file is eligible for it before assuming that payment is available to you.
• Balance over time — the year-by-year balance is exactly what a lender pulls when you request a mortgage statement or apply to refinance, and it is the figure that determines your available equity at any point during the term.
• Total interest — while lenders do not underwrite against this number directly, it is the clearest evidence for whether a shorter amortization, a larger down payment, or a disciplined extra-payment habit is worth the tighter monthly budget it requires.

Using your results well

Run the schedule once with no extras to see your baseline, then add a realistic extra payment and compare the two totals side by side. The interest-saved figure is usually the most persuasive number on this page, and it is worth checking against a few different extra-payment amounts before deciding what you can sustain every period.

What this calculator deliberately does not model is a rate change. It assumes your current rate holds for the entire amortization, which will never be true in practice — you will renew at a new rate every term, typically every one to five years, and that new rate will reshape the remaining schedule. Treat this as the schedule under today's rate, not a forecast of your actual payoff date.

• Compare the base schedule against one with a realistic extra payment before committing to it
• Check your actual prepayment privilege limit before setting the extra-payment inputs — exceeding it triggers a penalty
• Watch the crossover year to see when your payments start building more equity than interest expense
• Remember this schedule assumes a constant rate — your real payoff date will shift at every renewal
• Use the report button for the full year-by-year table to keep alongside your mortgage documents

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