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Extra-Payment Mortgage Payoff Calculator

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See how much sooner a loan pays off, and how much interest you save, by adding a fixed extra amount to every monthly payment

Enter a loan's principal, rate, and term alongside a fixed extra amount you plan to pay every month, and see the baseline payoff schedule compared side by side against the accelerated one. It reuses the same amortizing-loan formula as the standard Loan / Mortgage Calculator for the required payment, then simulates applying the extra amount straight to principal each month until the balance hits zero, reporting the new payoff time, months saved, and total interest saved. It's aimed at answering one specific question: is a fixed extra payment worth committing to, and if so how much does it actually move the needle versus just letting the loan run its full term. A 0% interest loan is handled as a straight-line payoff rather than dividing by zero.

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How to use Extra-Payment Mortgage Payoff Calculator

  • 1.Enter the loan's principal, annual interest rate, and term, then add the fixed extra amount you plan to pay every month on top of the required payment.
  • 2.Compare the baseline payoff time and total interest against the accelerated numbers side by side.
  • 3.Adjust the extra payment amount to see how sensitive the payoff time and interest savings are to how much extra you commit each month.

Frequently asked questions

Does this account for one-time lump-sum extra payments instead of a recurring monthly amount?
No, it models a fixed extra amount applied every single month for the life of the loan, not a one-time lump sum. A one-time extra payment would need a different simulation.
Does it account for taxes, insurance, or lender fees?
No, it computes the standard amortizing-loan payment and payoff schedule from principal, rate, and term only, the same core math the Loan / Mortgage Calculator uses before taxes, PMI, or escrow are layered on top.
What happens with a 0% interest loan?
A 0% rate is handled as a straight-line principal payoff instead of running the compound-interest formula, so an extra payment simply divides the remaining balance across fewer months without dividing by zero.
Is my loan data sent anywhere?
No, the calculation runs entirely in your browser. Nothing is transmitted to a server or stored.

Use via API, SDK, or MCP

cURL# Free: 1,000 req/day · Pro: 10,000 req/day
curl -X POST https://api.utilix.tech/v1/tools/extra-payment-mortgage-calculator \
  -H "Authorization: Bearer utx_live_..." \
  -H "Content-Type: application/json" \
  -d '{"principal":200000,"annualRatePercent":6,"termMonths":360,"extraMonthlyPayment":200}'

Get an API key from your dashboard · Full API docs →

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