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Mortgage Payoff Calculator
One extra payment a month sounds small until you see the receipt. This mortgage payoff calculator shows the new payoff date it buys you, the months it cuts from your loan and the interest you never pay.
See how this works on a $300,000 mortgage — 3 real examples
None yet — add a bonus or windfall to see its effect.
Interest saved by paying $200/mo extra
$0
That’s 0% of the interest left on your loan.
Time saved
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New payoff date
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Paid off in
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New monthly payment
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Balance over time: original vs. accelerated
Original vs. accelerated payoff
| Original | With extra | Change | |
|---|---|---|---|
| Monthly payment (P&I) | — | — | — |
| Payoff | — | — | — |
| Remaining interest | — | — | — |
| Total of payments | — | — | — |
Year-by-year payoff scheduleAccelerated vs original
Principal and interest follow the accelerated plan; the last column tracks the original schedule for comparison.
| Year | Principal paid | Interest paid | Balance (with extra) | Balance (original) |
|---|
How the amortization math behind your mortgage payoff works
Your current principal-and-interest payment M comes from the standard amortization formula on the balance P, monthly rate r (annual rate ÷ 12) and remaining months n. Raising the payment to M′ = M + extra shortens the term to:
n′ = −ln(1 − P·r / M′) / ln(1 + r)
and the headline number is interest saved = (M·n − P) − (M′·n′ − P). Rather than stopping at the closed form, the calculator simulates both schedules month by month — each month’s interest is balance × r, the rest of the payment reduces principal, and the final payment is clamped so the balance lands exactly on zero. That makes the short last payment, the chart and the table agree to the penny. Any one-time payments you add are applied to principal in the month you choose (and marked on the chart). Assumptions: a fixed rate, the extra amount applied to principal starting with your next payment, no prepayment penalty, and escrow items (taxes, insurance) excluded because they don’t affect the payoff. Payoff dates assume your next payment is one month from today.
Three sizes of extra, three finish lines
The same $300,000 at 6.5% with 25 years to run; all that changes is what rides along with the $2,025.62 payment.
The gentle push: $100 extra
interest saved$38,719
- An extra $100 beside the required $2,025.62 closes the loan at month 268 instead of 300.
- Thirty-two monthly payments — 2.7 years of them — never happen at all.
- Interest falls from $307,686 to $268,967, a bigger saving than all the extra payments put together.
The smallest extra still ends the loan 32 months early and keeps $38,719.
Load this example (opens in a new tab)Doubling down: $200 extra
interest saved$68,042
- At $200 a month the finish line moves up to month 243 — a 4.8-year head start.
- Lifetime interest drops to $239,645, a saving of $68,042.
- Compared with the $100 push, the head start grows by 25 months and the saving by $29,323.
A $200 habit erases nearly five years of payments and $68,042 of interest.
Load this example (opens in a new tab)The big swing: $500 extra
interest saved$125,588
- Five hundred extra retires the loan at month 191, a full 9.1 years ahead of schedule.
- Interest over the life of the loan falls to $182,098, down from $307,686.
- Five times the $100 extra buys more than three times its saving, and more than three times the years.
More than a third of the remaining 25 years, gone for $500 a month.
Load this example (opens in a new tab)Illustrations only, not financial advice. Your own rate, taxes and insurance will differ — check with a qualified financial advisor before acting on any of this.
Accelerated mortgage payoff, in plain English
- Interest is front-loaded. Early in the loan most of each payment is interest, so an extra dollar now cancels far more interest than the same dollar in year 20.
- Extra goes straight to principal. $200/mo on the default loan erases ~$68,000 and nearly five years — and one-time lump sums (a bonus or refund) work the same way.
- Prepay vs invest. Prepaying is a guaranteed return equal to your rate; at 6–7% that’s competitive with risky market returns — fund emergencies, the 401(k) match and high-interest debt first.
- Biweekly ≈ one extra payment a year. Simulate it by entering one-twelfth of your P&I as the monthly extra; skip third-party programs that charge fees.
- Shorter term, not lower payment. Extra payments end the loan sooner; for a lower required payment instead, ask about a recast.
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Frequently asked questions
How much can I save by paying off my mortgage early?
It depends on your balance, rate and how much extra you pay. On a $300,000 balance at 6.5% with 25 years left, adding just $200 a month saves roughly $68,000 in interest and pays the loan off about 4 years 9 months early. Because mortgage interest is front-loaded, extra dollars paid in the early years save the most. Enter your remaining balance into this mortgage payoff calculator and it estimates your own interest and time saved instantly.
Should I make extra mortgage payments or invest the money?
Prepaying earns a guaranteed return equal to your mortgage rate — 6.5% in the default scenario — while investing offers a higher expected but not guaranteed return (US stocks have averaged about 10% per year long-term). Most planners suggest funding an emergency fund, capturing any employer 401(k) match and clearing high-interest debt first, then splitting based on your rate and risk tolerance. At rates above 6%, prepaying is a strong risk-free option.
How do biweekly mortgage payments work?
You pay half your monthly payment every two weeks — 26 half-payments, or 13 full payments per year instead of 12. That works out to one extra payment annually, which you can simulate here by entering one-twelfth of your principal-and-interest payment as the extra amount (about $169 on a $2,026 payment). Make sure your servicer applies each half-payment when received rather than holding it, and skip third-party biweekly programs that charge setup fees for something you can do free.
Will I be charged a prepayment penalty for paying off early?
Most US mortgages originated after 2014 have no prepayment penalty — federal rules sharply restrict them on qualified mortgages. Where penalties exist, they typically apply only in the first three years of the loan. Check the "prepayment" clause in your loan note or ask your servicer before making large extra payments.
Does paying extra reduce my monthly payment or shorten my term?
By default it shortens your term: the required payment stays the same, and the extra principal simply ends the loan sooner — that is what this home mortgage payoff calculator models. If you want a lower required payment instead, ask your servicer about a recast: after a lump-sum payment they re-amortize the remaining balance over the same term, usually for a small fee.
How do I make sure my extra payment goes to principal?
Tell your servicer explicitly to apply the extra amount to principal — most online portals have an "apply to principal" option when you pay. If you do not, some servicers hold the money toward your next payment or route it to escrow, which saves you nothing. Check your next statement to confirm the balance dropped by the extra amount.
Is one big yearly payment as good as a monthly extra payment?
Almost, but not quite. $2,400 once a year and $200 every month total the same, but the monthly version reduces your balance sooner, so each dollar stops interest a few months earlier and saves slightly more overall. The difference is small — pick whichever pattern your cash flow actually sustains, because consistency matters far more than timing.
Disclaimer: these calculators are educational tools, not financial advice. They model your inputs with published formulas, but they cannot know your full situation — for decisions with real stakes, talk to a qualified professional. Formulas and defaults last reviewed .