Pay It Faster Calculator (years and interest saved)
One extra shift a month. Years off the mortgage. Paid duty, overtime, a side detail — money that lands on top of base pay can land on top of the mortgage instead of disappearing. This calculator simulates it month by month: what an extra amount every month, or a lump sum every year, does to the payoff date and the interest bill.
Your numbers
One paid-duty shift a month? Put what you actually clear from it here.
Tax refund, retro pay, a bonus — applied straight to principal once a year.
Required payment on your current schedule: $3,231.56/mo.
Mortgage-free
4 years 3 months sooner
Interest saved: $89,321
The payoff, drawn to scale
One caveat: lenders cap penalty-free prepayments — commonly a percentage of the original principal per year, and the percentage varies by lender and contract. Those caps are contract terms, not public rules, so this calculator doesn’t guess them. Before committing to a plan, have us check your contract’s privileges — and if the plan outgrows them, that’s a renewal conversation worth having early.
The rules this runs on — and how the math was verified
Canadian semi-annual compounding; the extras go straight to principal — the monthly extra with every payment, the lump after each twelfth payment. The simulation runs month by month because prepayment math has no shortcut once lump sums enter.
The engine passes 24 automated checks — with zero extras it must reproduce the closed-form amortization exactly, hand-computed zero-rate cases must land to the month, an independently-written second simulation must agree to the cent, and more extra money must never pay off later. Arithmetic last verified October 15, 2026. It’s an illustration, not a quote or a commitment to lend.
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