Mortgage Prepayment Calculator — Extra Payments, Payoff & Penalties
By Hami Tahm · Last reviewed July 2026
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Model lump sums, extra monthly payments, and accelerated frequency — see interest saved and your new payoff date with Canadian semi-annual compounding.
What does Canada's mortgage prepayment calculator show?
Canada's mortgage prepayment calculator estimates how extra payments, lump sums, or accelerated payment frequency reduce your amortization and total interest cost. Enter your current mortgage balance, remaining amortization, interest rate, and the extra amount you plan to pay — monthly, annually, or as a one-time lump sum. The calculator also estimates your prepayment penalty if you break a closed mortgage before maturity, using both the 3-month interest method and the Interest Rate Differential (IRD) formula.
Prepayment penalty estimates vary by lender. This calculator estimates your prepayment penalty using standard IRD and 3-month interest formulas. Actual penalties depend on your specific lender's posted rate schedule, how they define the "comparison rate" for IRD, and any unique terms in your mortgage contract. Always confirm your exact penalty amount with your lender before breaking a mortgage. On some mortgages, the penalty can exceed $20,000.
Calculate Your Prepayment Savings
Mortgage Details
Mortgage-Free
7 years 3 months sooner
Interest Saved
$96,187
New Payoff
April 2044
Original Payoff
July 2051
Total Saved
$96,187
| Without | With Prepayments | |
|---|---|---|
| Regular Payment | $2,326 | $2,326 |
| Extra Per Period | — | $500 |
| Total Per Period | $2,326 | $2,826 |
| Payoff Date | July 2051 | April 2044 |
| Total Interest | $297,926 | $201,739 |
| Total Amount Paid | $697,926 | $601,739 |
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Prepayment Penalty — If You Break Your Mortgage
Breaking a closed mortgage before the end of your term triggers a penalty. On a variable rate it is 3 months' interest. On a fixed rate it is the greater of 3 months' interest and the Interest Rate Differential (IRD).
Your lender's current posted rate for a term closest to the time left in yours.
3 months' interest
$5,000
IRD
$18,000
Estimated penalty (IRD)
$18,000
Estimate only. Lenders each define the "comparison rate" differently — some use posted rates, which produces a much larger IRD than a discounted rate would. Ask your lender for the exact figure in writing before you break your mortgage.
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Key Takeaways
- On a $500,000 Canadian mortgage at 5.00% over 25 years, making one extra monthly payment per year reduces the amortization by more than 3 years and saves approximately $59,000 in total interest — at no additional monthly commitment beyond one annual lump sum.
- Most closed Canadian mortgages allow annual prepayments of 10% to 20% of the original balance without penalty — on a $500,000 mortgage, that is $50,000 to $100,000 per year that can be applied to principal at zero cost.
- The IRD penalty on a fixed-rate mortgage can be many times larger than the 3-month interest penalty when rates have fallen sharply — on a $450,000 mortgage with a 1% rate differential and 3 years remaining, the IRD is $13,500 versus a 3-month interest penalty of $5,625.
- Combining accelerated biweekly payments with an additional $200 per month on a $500,000 mortgage at 5% reduces a 25-year amortization to approximately 19 years — eliminating more than 6 years of payments and saving approximately $94,000 in interest.
The Math — Step-by-Step
Year-by-Year Comparison
| Year | Balance (No Prepay) | Balance (With Prepay) | Difference | Interest Saved | Prepayments |
|---|---|---|---|---|---|
| Year 1 | $391,691 | $385,553 | $6,138 | $138 | $6,000 |
| Year 2 | $382,961 | $370,375 | $12,587 | $449 | $6,000 |
| Year 3 | $373,790 | $354,428 | $19,362 | $775 | $6,000 |
| Year 4 | $364,154 | $337,674 | $26,480 | $1,118 | $6,000 |
| Year 5 | $354,030 | $320,071 | $33,959 | $1,479 | $6,000 |
| Year 6 | $343,394 | $301,578 | $41,816 | $1,857 | $6,000 |
| Year 7 | $332,219 | $282,148 | $50,071 | $2,255 | $6,000 |
| Year 8 | $320,479 | $261,735 | $58,743 | $2,673 | $6,000 |
| Year 9 | $308,144 | $240,289 | $67,855 | $3,112 | $6,000 |
| Year 10 | $295,185 | $217,756 | $77,428 | $3,573 | $6,000 |
| Year 11 | $281,569 | $194,083 | $87,486 | $4,058 | $6,000 |
| Year 12 | $267,265 | $169,212 | $98,053 | $4,567 | $6,000 |
| Year 13 | $252,236 | $143,081 | $109,155 | $5,102 | $6,000 |
| Year 14 | $236,446 | $115,627 | $120,819 | $5,664 | $6,000 |
| Year 15 | $219,857 | $86,784 | $133,073 | $6,254 | $6,000 |
| Year 16 | $202,429 | $56,480 | $145,948 | $6,875 | $6,000 |
| Year 17 | $184,118 | $24,643 | $159,475 | $7,527 | $6,000 |
| Year 18 | $164,880 | $0 | $164,880 | $8,173 | $4,500 |
| Year 19 | $144,668 | — | $144,668 | $7,705 | — |
| Year 20 | $123,432 | — | $123,432 | $6,682 | — |
| Year 21 | $101,122 | — | $101,122 | $5,607 | — |
| Year 22 | $77,682 | — | $77,682 | $4,477 | — |
| Year 23 | $53,056 | — | $53,056 | $3,291 | — |
| Year 24 | $27,183 | — | $27,183 | $2,044 | — |
| Year 25 | $0 | — | $0 | $734 | — |
| Total | $96,187 | $106,500 |
What Does This Prepayment Calculator Show?
The mortgage prepayment calculator produces three key outputs. First: your new amortization — the number of years and months your mortgage will take to pay off with the extra payments applied. Second: the total interest saved compared to making only scheduled payments. Third: your estimated payoff date — the specific month and year your mortgage balance reaches zero. For lump sum inputs, the calculator applies the payment to the principal immediately and recalculates from that point forward.
Extra Monthly Payments — Amortization & Interest Saved
Extra monthly payments reduce your principal with every payment cycle. Because Canadian mortgage interest is calculated on the outstanding balance semi-annually, a lower balance means less interest accruing in every subsequent period. This calculator shows you the exact number of months removed from your amortization for any monthly extra payment amount you enter.
Lump Sum Prepayments — One-Time Impact
A lump sum prepayment is applied directly to your mortgage principal on the date of payment. The calculator models the lump sum as applied on your mortgage anniversary date — the typical window specified in Canadian mortgage contracts. The effect compounds over the remaining amortization: a $25,000 lump sum in year one on a $500,000 mortgage at 5.00% saves approximately $56,249 in interest. Mortgage lump sum payment strategies work best when applied early in the amortization.
Payoff Date — How Many Years Sooner?
The payoff date is the specific month and year your mortgage balance reaches zero. With extra payments, the calculator recomputes your full amortization schedule from the current balance forward and reports the new payoff month. For combined strategies — extra monthly plus annual lump sum — the two effects are modelled together in a single schedule.
How Extra Mortgage Payments Work in Canada
Most Canadian closed mortgages allow annual prepayments of 10% to 20% of the original mortgage balance without penalty — these are called prepayment privileges. Making one extra monthly payment per year on a $500,000 mortgage at 5.00% over 25 years reduces the amortization by more than 3 years and saves approximately $59,000 in interest. A $25,000 lump sum in year one produces similar savings of approximately $56,000. Payments above your prepayment privilege may trigger a prepayment penalty.
Annual Prepayment Privilege — Typically 10–20% of Original Balance
Most closed Canadian mortgages allow annual prepayments of 10% to 20% of the original balance without penalty — on a $500,000 mortgage, that is $50,000 to $100,000 per year that can be applied to principal at zero cost. The privilege resets on your mortgage anniversary date each year — unused amounts do not carry forward. Lender-specific limits vary; confirm your exact privilege in your mortgage agreement.
Your prepayment privilege resets each year — unused privilege does not carry forward. Exceeding your limit, even by $1, can trigger a prepayment penalty. Confirm your specific annual limit in your mortgage agreement before making a large payment.
| Lender | Annual Lump Sum | Payment Increase | Notes |
|---|---|---|---|
| RBC | Up to 10% | Up to 10% | Some products offer 20/20 — check your mortgage agreement |
| TD | Up to 15% | Up to 100% doubling | TD allows payment doubling on some products |
| Scotiabank | Up to 15% | Up to 15% | STEP mortgage has different rules |
| BMO | Up to 20% | Up to 20% | 20/20 on most closed fixed products |
| CIBC | Up to 20% | Up to 100% doubling | Payment doubling option available |
| National Bank | Up to 10% | Up to 10% | Confirm per product |
| Credit Unions | Varies | Varies | Often more flexible than Big 6 — review your agreement |
Limits vary by product and mortgage agreement. The figures above are indicative only. Confirm your specific prepayment privilege in your mortgage agreement or by contacting your lender directly.
One Extra Payment Per Year — Worked Example
On a $500,000 Canadian mortgage at 5.00% over 25 years, making one extra monthly payment per year reduces the amortization by more than 3 years and saves approximately $59,000 in total interest — at no additional monthly commitment beyond one annual lump sum. The table below compares five prepayment strategies on the same baseline.
| Extra Payment Type | New Amortization | Yrs Saved | Interest Saved |
|---|---|---|---|
| No extra (baseline 25yr) | 25yr 0mo | — | — |
| +$200/month | 22yr 1mo | 2.9 | $50,018 |
| +$500/month | 18yr 10mo | 6.2 | $103,139 |
| 1 extra payment/year | 21yr 7mo | 3.4 | $58,830 |
| $25K lump sum (year 1) | 22yr 9mo | 2.2 | $56,249 |
| Accel biweekly + $200/mo | 19yr 5mo | 5.6 | $94,403 |
Assumptions: $500,000 mortgage, 5.00% annual rate, 25-year amortization, Canadian semi-annual compounding (Interest Act). Monthly payment baseline: $2,908. Lump sum applied annually on anniversary date.
Source: Financial Consumer Agency of Canada (FCAC) — FCAC mortgage prepayment privileges guide. Prepayment privilege limits are set by your mortgage contract, not by federal regulation. Confirm your specific limits directly with your lender.
Mortgage Payoff Calculator — Paying Off Early
The payoff calculator estimates how long it will take to reach a zero balance given extra payments above your scheduled amount. On a $500,000 mortgage at 5.00% with a 25-year amortization, adding $500 per month to the regular payment shortens the payoff period by more than 6 years and reduces total interest paid by approximately $103,000. The payoff date calculation adjusts for Canadian semi-annual compounding and the specific principal balance at each point in the amortization schedule.
How the Payoff Date Is Calculated
The calculator builds a full amortization schedule using Canadian semi-annual compounding — required by the Interest Act for all Canadian mortgages. The effective monthly rate is derived using the formula: (1 + annual rate ÷ 2)^(1/6) − 1. Extra monthly payments are added to each payment in the schedule; lump sums reduce the principal at the anniversary date. The calculator recomputes month by month until the balance reaches zero.
Interest Saved by Paying Off 5 Years Early
On a $500,000 mortgage at 5.00% over 25 years, adding $500 per month in extra payments shortens the payoff period by more than 6 years and reduces total interest paid by approximately $103,000. Earlier extra payments save more because they reduce the principal on which interest compounds for a longer period. Use the year-by-year comparison table above to see exactly how your balance diverges from the no-prepayment baseline each year.
For a deeper look at how lump-sum and accelerated payments affect your full amortization schedule, see our companion post on building a Canadian mortgage calculator in Excel.
▶ Want to see your full year-by-year payment schedule?
Prepayment Penalty Calculator — IRD and 3-Month Interest
If you break a closed fixed-rate mortgage before maturity, the penalty is the higher of: three months' interest on the outstanding balance, or the Interest Rate Differential (IRD). The IRD is calculated as: (your contract rate minus the lender's current posted rate for the remaining term) multiplied by the outstanding balance multiplied by the remaining years. On a $450,000 balance with 3 years remaining at a contract rate of 5.00% and a current 3-year posted rate of 4.00%, the IRD penalty is approximately $13,500; the 3-month interest penalty is approximately $5,625 — so the IRD applies.
Variable Rate Mortgages — 3-Month Interest Formula
Variable-rate mortgage holders in Canada always pay the simpler 3-month interest penalty when breaking a mortgage — the IRD formula does not apply to variable-rate products, which is one reason variable rates have historically attracted more penalty-conscious borrowers. The formula is: outstanding balance × (annual rate ÷ 12) × 3. On a $450,000 balance at 5.00%, this is approximately $5,625.
Fixed Rate Mortgages — Interest Rate Differential (IRD)
The IRD penalty on a fixed-rate mortgage can be many times larger than the 3-month interest penalty when rates have fallen sharply — on a $450,000 mortgage with a 1% rate differential and 3 years remaining, the IRD is $13,500 versus a 3-month interest penalty of $5,625. Canadian lenders are required by the Interest Act to disclose prepayment penalties before a borrower breaks a closed mortgage — but the exact penalty formula differs by lender, making independent estimation essential before any decision.
Before breaking your mortgage, confirm your exact penalty with your lender. This calculator provides estimates only — actual IRD depends on your lender's specific posted rate schedule and methodology. See the FCAC guide to breaking a mortgage contract for your rights and options.
| Mortgage Type | Penalty Method | Outstanding Bal. | Rate Differential | Penalty |
|---|---|---|---|---|
| Variable rate | 3-month interest | $450,000 | N/A | $5,625 |
| Fixed — IRD applies | IRD (rates fell) | $450,000 | 1.00% (5% vs 4%) | $13,500 |
| Fixed — 3-mo applies | 3-month interest | $450,000 | N/A (rates rose) | $4,500 |
Fixed — 3-month applies: contract rate 4.00%, current posted rates have risen so IRD is zero; 3-month penalty = $450,000 × 4.00% × 3/12 = $4,500. All figures are illustrative — actual penalties depend on your lender's methodology and mortgage contract.
How to Calculate a Mortgage Prepayment Penalty (IRD) in Canada — Step by Step
- 1Find your contract rate and remaining term. Locate your mortgage contract or most recent renewal statement. Note your contract interest rate (e.g., 5.00%) and count the number of months remaining in your current term (e.g., if your term matures in 3 years, you have approximately 36 months remaining).
- 2Find your lender's current posted rate for the remaining term. Check your lender's website for the current posted rate on a term equal to your remaining months. If 3 years remain, look up the posted 3-year fixed rate. Posted rates differ from discounted rates — use the posted rate for the IRD calculation, not the rate you are being offered to new customers.
- 3Calculate the rate differential. Subtract the current posted rate from your contract rate. Example: 5.00% (contract) minus 4.00% (current posted 3-year) = 1.00% rate differential. If the result is negative (rates have risen), your IRD is zero — the 3-month interest penalty will apply instead.
- 4Apply the IRD formula. Multiply: outstanding balance × rate differential × remaining years. Example: $450,000 × 1.00% × 3 years = $13,500 IRD. This is the IRD penalty if you break the mortgage today. Note: some lenders use remaining months divided by 12 rather than whole years — verify your lender's exact methodology.
- 5Compare to the 3-month interest penalty and take the higher. Calculate the 3-month interest penalty: outstanding balance × contract rate × 3/12. Example: $450,000 × 5.00% × 3/12 = $5,625. Compare to IRD of $13,500. Your lender charges whichever is greater — in this case, the IRD of $13,500 applies. The 3-month interest method is always the floor for fixed-rate mortgages.
Biweekly Payments vs. Extra Monthly Payments — Which Saves More?
Accelerated biweekly payments and extra monthly payments are both prepayment strategies — but they work differently. Accelerated biweekly payments effectively add one extra monthly payment per year by splitting your monthly payment into 26 half-payments annually. Adding a fixed extra dollar amount monthly is more flexible and compounds faster if the amount is significant. Combining both strategies — accelerated biweekly plus an extra $200/month — on a $500,000 mortgage at 5% reduces the 25-year amortization to approximately 19 years and saves approximately $94,000 in interest.
Accelerated Biweekly as a Prepayment Strategy
The accelerated biweekly option is built into most Canadian mortgage contracts — but many homeowners are on the regular biweekly schedule without realising the difference. Regular biweekly = 26 payments of half your monthly payment = equivalent to 12 full monthly payments per year. Accelerated biweekly = 26 payments at half the monthly rate = equivalent to 13 full payments per year. Confirm with your lender that you are on the accelerated biweekly schedule, not the regular one. The word "accelerated" is what produces the extra payment and where all the savings come from. This is available to any homeowner — no lender approval needed, no privilege limit consumed.
Combining Accelerated Payments With Lump Sums
Combining accelerated biweekly payments with an additional $200 per month on a $500,000 mortgage at 5% reduces a 25-year amortization to approximately 19 years — eliminating more than 6 years of payments and saving approximately $94,000 in interest. For maximum payoff speed, layering an annual mortgage lump sum payment on your anniversary date on top of this combination produces the greatest total reduction. The biweekly mortgage calculator with extra payments feature above models all combinations simultaneously.
Sources
- Financial Consumer Agency of Canada (FCAC) — Breaking a mortgage contract
- Financial Consumer Agency of Canada (FCAC) — FCAC mortgage prepayment privileges guide
- Government of Canada — Interest Act — mortgage penalty rules
- Office of the Superintendent of Financial Institutions (OSFI) — Residential mortgage underwriting practices and procedures
Frequently Asked Questions
Disclaimer: estimates only. This calculator provides estimates only. Actual prepayment penalties depend on your lender's specific formula, posted rate schedule, and mortgage contract terms. Actual interest savings depend on your mortgage terms and payment schedule. Consult a licensed mortgage professional before making any prepayment decisions or breaking a mortgage contract.
▶ Know your baseline payment before calculating prepayment savings.
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