Mortgage Payoff Calculator (Pay Off Your Mortgage Early)
Start from what you owe today, add an extra monthly amount, and see how many years disappear from your mortgage, the interest you save, and your new payoff date, side by side with the current plan.
What you owe today, from your latest statement
The annual rate on your mortgage
I know my...
Time left on the loan at the scheduled payment
Additional principal on top of the scheduled payment
Time shaved off
5 years 3 months
debt-free around May 2046 instead of Aug 2051
Interest saved
$61,869
$192,673 instead of $254,542 in remaining interest
New payoff timeline
19 years 9 months
sending $1,915/mo, done around May 2046
Current plan vs. with the extra payment
| Metric | Current plan | With $200 extra |
|---|---|---|
| Monthly payment | $1,715 | $1,915 |
| Time to payoff | 25 years | 19 years 9 months |
| Payoff date | Aug 2051 | May 2046 |
| Remaining interest | $254,542 | $192,673 |
| Total still to pay | $514,542 | $452,673 |
Assumes a fixed rate, no prepayment penalty, and every extra dollar applied to principal. Taxes, insurance, and escrow are not included and don't change with prepayment.
What an extra payment actually buys
A mortgage payment covers the month's interest first; only the remainder reduces the balance. An extra payment skips that split, because the interest is already paid, and lands entirely on principal. That does two things at once: it moves the payoff date closer, and it deletes every future interest charge that slice of principal would have generated. On a long loan the second effect dominates, which is why modest extras produce outsized savings. The effect is strongest early in the term, when the amortization curve is at its most interest-heavy.
Run the numbers: $260,000 with 25 years left
Say you owe $260,000 at 6.25% with 25 years remaining, a scheduled payment of about $1,715. Left alone, that path pays roughly $255,000 more in interest. Add $200 a month and the loan ends about 5 years and 3 months early, with total remaining interest near $193,000: about $62,000 saved for $200 a month you controlled the whole time. Prepayment is also flexible in a way a refinance isn't: you can pause the extra in a tight month with no paperwork and no closing costs. If a payment cut is what you actually need, compare this against the refinance calculator before committing either way.
Before you send the first extra dollar
Three checks keep the strategy honest. First, higher-rate debt: a credit card at 22% beats a mortgage at 6% for every spare dollar, every time. Second, your cash cushion: extra principal is locked in the house and only comes back out through a sale or a loan, so an emergency fund comes first. Our save-or-invest guide walks the full ordering. Third, confirm your servicer applies extras to principal rather than parking them against next month's bill. If a fixed extra feels hard to start, the biweekly mortgage calculator shows a schedule trick that hides one extra payment a year inside your normal cash flow.
Frequently asked questions
Do extra payments lower my monthly mortgage payment?
Typically no. The required payment stays the same; the loan simply ends earlier because the balance falls faster. Some servicers offer a recast, where a fee re-spreads the smaller balance over the remaining term to lower the payment, but the default result of prepaying is a shorter loan, not a cheaper month.
Is it better to pay extra monthly or once a year?
Sooner beats later, dollar for dollar. Principal removed in January saves more interest than the same amount removed in December, because it stops accruing interest for longer. In practice, a monthly habit you actually keep usually outperforms a year-end lump sum you might skip.
How do I make sure the extra goes to principal?
Tell your servicer explicitly. Many payment portals have an "apply to principal" option; without it, extra money is sometimes held as a prepayment of next month's bill, which saves you nothing. Check the next statement to confirm the balance dropped by the full extra amount.
Should I pay off my mortgage early or invest instead?
Prepaying is a guaranteed, tax-free return equal to your mortgage rate. Against a 7% mortgage that's a strong, riskless result; against a 3% one, long-run market returns usually win. Most orderings put an employer 401(k) match and high-rate debt first, and treat mortgage prepayment as a judgment call after those.
Do mortgages have prepayment penalties?
Most U.S. mortgages written in recent years allow penalty-free prepayment, but some loans carry a penalty in the first few years. Your closing paperwork or servicer can confirm. If a penalty exists, it usually fades on a schedule, and the math here still works once it does.
Does this calculator save my numbers?
No. Everything runs in your browser and nothing you type is stored or sent anywhere.
Want this to update itself?
Stoia connects your real accounts and keeps the full picture current: net worth, budgets, and goals. Launching in 2026.