Mortgage Payoff Calculator
See how extra monthly or one-time payments shorten your mortgage and cut total interest, calculated in your browser.
The Mortgage Payoff Calculator runs entirely in your browser. Your balance, rate, and payment figures never leave your device, and the results are estimates only, not financial advice.
Open the Mortgage Calculator
About Mortgage Payoff Calculator
The Mortgage Payoff Calculator shows how adding extra money to your monthly mortgage payment — or making a one-time lump-sum payment — shortens your loan and cuts the interest you'll pay over the remaining term. Enter your current balance, interest rate, and remaining months, then add an extra monthly amount and/or a one-time payment to see the new payoff date side by side with your original schedule. It reports months saved, interest saved, and the new regular payment so you can decide if paying down principal faster is worth it. Built for homeowners comparing payoff strategies before committing extra cash to their mortgage. Everything runs locally in your browser, and these are estimates only — not financial advice.
Features
- Compares your original payoff schedule against one with extra payments
- Accepts an extra recurring monthly payment, a one-time payment, or both
- Shows months saved and total interest saved side by side
- Reports the standard fixed monthly payment for your current balance and term
- Handles a 0% rate as straight-line amortization
- Copy a plain-text summary of the payoff comparison
- Clear error messages for an invalid balance, rate, or term
- Runs entirely in your browser with no loan details sent anywhere
How to use the Mortgage Payoff Calculator
- Enter your remaining balance, annual interest rate, and remaining term in months
- Add an extra monthly payment amount, a one-time payment, or both
- Read the months saved and interest saved compared to your original schedule
- Copy the summary to share with a partner or your loan servicer
Example
Input
$250k @ 6%, 300 mo, +$200/mo
Output
Payoff 47 months sooner
Interest saved: $56,700
Common errors & troubleshooting
- Interest rate entered as a decimal like 0.06 instead of 6. — Enter the annual rate as a percentage — type 6 for 6%, not 0.06. The calculator treats the rate field as already-a-percent.
- Remaining term entered in years instead of months. — The term field expects months. A 25-year remaining term is 300 months, not 25.
- Extra payment shows no time or interest saved. — Make sure the extra monthly or one-time field has a positive number — an empty or zero extra payment reproduces the original schedule exactly.
- Results look off after refinancing or a rate change. — Use your current post-refinance balance, rate, and remaining term, not the original loan's figures — the calculator only knows what you enter.
Frequently asked questions
- What does the Mortgage Payoff Calculator actually compute?
- It amortizes your remaining mortgage balance twice — once on the original schedule and once with your extra monthly and/or one-time payments applied — then reports the difference in months and total interest.
- Does the Mortgage Payoff Calculator account for refinancing?
- No. It works from the balance, rate, and remaining term you enter today. If you refinance, re-run the calculator with the new loan's figures.
- Can I model both a monthly extra payment and a one-time lump sum together?
- Yes. Fill in both the extra monthly payment and the one-time payment fields and the calculator applies the lump sum immediately, then the extra amount every month after.
- Is the mortgage payoff estimate exact?
- It's a close estimate based on standard amortization math. Your lender's actual schedule, escrow handling, and any prepayment penalties can shift the real numbers, so this is not financial advice — check with your loan servicer.
- Does extra mortgage payoff always save interest?
- Yes, as long as your loan has no prepayment penalty — extra principal payments always reduce future interest, since interest is calculated on a smaller remaining balance each month.
- Does the calculator upload my loan balance or rate?
- No. The Mortgage Payoff Calculator runs entirely in your browser. The balance, rate, and payment amounts you enter never leave your device.
Related tools
- Mortgage Calculator — Estimate monthly mortgage payments including principal, interest, taxes and insurance.
- Amortization Calculator — Build a full loan amortization schedule showing principal and interest for each payment.
- Refinance Calculator — Compare your current mortgage to a refinance and find the break-even point.
- Loan Calculator — Calculate the monthly payment, total interest and payoff of any amortized loan.
- Debt Payoff Calculator — Plan a debt-free date with the avalanche or snowball method across multiple debts.
- Interest Rate Calculator — Solve for the interest rate of a loan from its amount, payment and term.
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