What would an extra payment save you?
See the interest you'd avoid and the years you'd cut off your mortgage, calculated on your real balance.
Roughly how much longer you have to pay, not the loan’s original term.
Type in your balance and rate. Then see what a bit more each month saves you.
Tell your servicer to apply it to principal. An extra amount sent without instructions is often credited toward next month's bill instead, which doesn't change your balance or these numbers. See how extra payments actually hit your amortization.
Paying extra shortens the loan; it doesn't reduce your required monthly payment. If a lower payment is the goal, that's a recast or refinance.
These are estimates, not advice. Check with your lender. Your numbers stay in your browser.
How this works
We rebuild your real amortization schedule
We map your balance, your rate, and your years left, month by month. Then we build the whole thing again with your extra payment in it. The gap between the two is your saving. It is not a rough rule.
Monthly extras and lump sums both count
Add a set amount each month, a one off sum, or both. A lump sum today does not do the same work as the same cash spread over a year. This tool shows that.
PMI comes off sooner, and we show it
Paying more gets you to the 80% mark early. Add what the home was worth, and what PMI costs you. Then we price that saving next to the rest.
Estimates only, not financial or legal advice. Verify with your lender.
Common questions
It depends almost entirely on your rate and how much of the loan is left. On a $340,000 balance at 6.5% with 30 years to run, an extra $100 a month saves roughly $70,000 in interest and clears the loan about 4 years early. The same $100 on a loan with 8 years left saves a few thousand. Enter your own balance above rather than relying on a rule of thumb, because the gap between those two cases is enormous.
You are charged on what you still owe. So a dollar paid today saves you on every month that comes after. In the first years, most of your bill is interest and the balance hardly moves. That is just when an extra dollar has the most months to work. The same dollar in year 25 has almost no time left to help.
No. Extra principal shortens the loan; it does not reduce the payment your servicer requires each month. If a lower payment is what you need, the tools for that are a recast (same loan, re-amortized over the remaining term after a lump sum, typically a $150–500 fee) or a refinance (an entirely new loan, rate, and closing costs).
Yes, and this is the single most common way extra payments get wasted. An unlabeled extra amount is frequently applied to next month's bill instead of the balance, which pays you ahead in time but does nothing to your amortization or your PMI timeline. Designate it as "additional principal" in your servicer's portal or on the memo line, then check your next statement to confirm the balance dropped by the full amount.
It pulls in the date you can ask. The law lets you ask once you owe 80% of what the home was worth. Paying more gets you there sooner. But the 78% date is set by your first payoff plan. Extra payments cannot move that one. Add what the home was worth and what PMI costs to see the gap.
Paying more earns you a sure, tax free return at your loan rate. When rates are high that is a good, safe deal. Stocks may earn more over many years. But they carry risk, and nothing is sure. This tool shows just the loan side. Your answer also turns on your emergency fund, your 401(k) match, and any debt at a higher rate. This is not financial advice.
No. The calculation runs entirely in your browser and none of the figures you type are transmitted or stored.
Stop checking this by hand
Run your free health check once. Then we keep watching. We watch your PMI, your escrow, and today’s rates. And we tell you the day it is worth acting.