Mortgage Payoff Calculator
See how much sooner you pay off your mortgage and how much interest extra payments save.
Results update as you type.
About this calculator
Adding a little extra to your mortgage payment each month goes straight to principal, shortening the loan and cutting the interest you pay. This mortgage payoff calculator compares your current schedule with an accelerated one that adds your chosen extra monthly payment, plus an optional one-time lump sum, and shows the new payoff time and the total interest saved.
Because your regular payment is fixed, any amount above it has no interest to cover and reduces principal directly, so next month accrues less interest and the effect compounds. On a 250,000 balance with 25 years left at 6.5%, paying an extra 200 a month clears the loan years early and saves a substantial slice of interest, all reported against the baseline no-extra schedule.
Use it to see how much sooner extra payments free you from the mortgage and how much interest they save, and to compare steady monthly extras against a single lump sum. An earlier lump sum has more time to work, while regular extras compound their benefit across the whole remaining term.
Frequently asked questions
How do extra payments pay off a mortgage early?
Your regular payment is fixed, so any amount above it has no interest to cover and reduces the principal directly. A smaller principal accrues less interest next month, which snowballs — often cutting years off a 30-year loan for a modest monthly extra.
Is it better to pay extra monthly or one lump sum?
Both help; monthly extra payments compound their benefit over the whole term, while a lump sum has the biggest impact the earlier it lands. Enter either or both here to compare the interest saved.
How much sooner will extra payments pay off my mortgage?
It depends on the extra amount, your rate and years remaining, but the effect is often dramatic — a modest monthly extra can shave several years off a long balance. The tool’s time-saved figure shows exactly how many months you cut versus paying the minimum.
Is it better to pay off my mortgage early or invest?
Paying extra guarantees a return equal to your mortgage rate, tax-free of risk; investing might earn more but with uncertainty. If your rate is high, prepaying is attractive; if it is low, investing the same money may build more wealth over time.
Should I make a lump-sum payment or refinance instead?
A lump sum keeps your rate and term but knocks down principal immediately, saving interest without closing costs. Refinancing changes the rate or term and has fees. If your current rate is fine, extra principal payments are often the cheaper way to save interest.
Will extra mortgage payments lower my monthly payment?
No — your required monthly payment stays the same; extra payments shorten the loan and cut total interest instead. To actually reduce the monthly amount you would need to refinance or recast the loan, which this calculator does not model.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/mortgage-payoff/curl
curl "https://calculator.free/api/v1/mortgage-payoff/?balance=250000&rate=6.5&years=25&extra=200"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/mortgage-payoff/?" + new URLSearchParams({
"balance": "250000",
"rate": "6.5",
"years": "25",
"extra": "200"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.