Prepayment / Lump Sum Calculator
See exactly how much interest — and how much time — extra monthly or annual lump-sum payments can cut from your mortgage.
Type exact values (cents included) or drag a slider to get close. To fine-tune, click the slider and press Left arrow keyRight arrow key on your keyboard: each press moves mortgage amounts by $100 and interest rates by 0.01%.
Type an exact value from $100,000 to $1,500,000. Dragging the slider moves quickly. With the slider focused, press the left or right arrow key to move in steps of $100.
Type an exact value from 2.00% to 8.00%. Dragging the slider moves quickly. With the slider focused, press the left or right arrow key to move in steps of 0.01%.
Type an exact value from $0 to $2,000. Dragging the slider moves quickly. With the slider focused, press the left or right arrow key to move in steps of $25.
Type an exact value from $0 to $20,000. Dragging the slider moves quickly. With the slider focused, press the left or right arrow key to move in steps of $100.
Most lenders allow 10–20% in annual prepayments without penalty. Small extras early make the biggest difference.
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Get Exact Numbers — Free CallHow the Prepayment / Lump Sum Calculator Works
Most Canadian mortgages allow prepayment privileges — extra monthly payments and annual lump sums — without penalty, typically up to 10–20% of the original principal per year.
This calculator simulates your amortization with and without those extra payments so you can see the real interest savings and how much sooner you’d be mortgage-free.
4 Steps to Your Results
These set your baseline schedule with no extra payments.
Even a modest amount, like $200/month, compounds meaningfully over the life of a mortgage.
Many people apply a bonus, tax refund, or other windfall as a once-a-year lump sum.
See total interest with and without the extra payments, and exactly how much time is cut from your amortization.
On a $500,000 mortgage at 4.49% over 25 years, adding just $200/month in extra payments (with no lump sum) cuts the mortgage short by about 2 years, 11 months.
Total interest drops from $329,376 with no extra payments to $286,327 with the extra $200/month — an interest saving of about $43,049 over the life of the mortgage.
Add an annual lump sum on top in the calculator above to see how much further that timeline and interest total can shrink.
Frequently Asked Questions
Most lenders allow 10–20% of the original principal per year in extra payments without penalty — check your specific mortgage documents for your exact privilege.
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