Mortgage Payoff Calculator
How much extra payments save, and what it takes to be mortgage-free by a date you choose
Last updated: October 2026
Your Mortgage Today
Your Payoff Plan
Paid with every 12th payment, for example from a bonus or tax refund.
Used only for the investing comparison. An assumption, not a forecast.
Balance over time
| Current plan | With extras | |
|---|---|---|
| Monthly principal and interest | $2,025.62 | $2,325.62 |
| Payments left | 300 | 223 |
| Interest still to pay | $307,686 | $216,512 |
| Total extra paid | $0 | $66,600 |
How paying off a mortgage early works
Your required payment is fixed, and each month the lender takes interest on the balance first. Anything you pay above the required amount goes straight to principal. A lower balance means less interest next month, so more of the regular payment goes to principal too, and the effect builds on itself. The calculator runs your loan month by month twice, once as it is and once with your extra payments, and reports the difference in interest and in the number of payments.
To hit a target date, it works backwards: it finds the level payment that brings today's balance to zero in exactly the time you choose, then subtracts your current payment. That difference is the extra you need each month.
Worked example
You owe $300,000 at 6.5% with 25 years left. Your principal and interest payment is $2,025.62, and you are on course to pay $307,686 more in interest. Add $300 a month and the loan is gone in 18 years 7 months, 6 years 5 months early, with $91,174 less interest.
Want it paid off in 15 years instead? The payment that clears $300,000 at 6.5% in 180 months is $2,613.32, so you would need to add $587.70 a month.
Before you prepay
- Liquidity. Money paid into your home is hard to get back. Keep an emergency fund first.
- Higher-rate debt. Paying off a credit card at 20% beats prepaying a mortgage at 6.5%.
- Employer match. A 401(k) match is an immediate return that prepaying cannot equal.
- Prepayment terms. Confirm your loan has no prepayment penalty and that extra amounts are applied to principal.
- Lower payment instead? Extra payments shorten the loan but do not cut the required payment. A mortgage recast does.
Related tools and reading
See every payment month by month in the amortization schedule calculator, or start from the main mortgage calculator. Paying half your payment every two weeks is another way to make one extra payment a year: try the bi-weekly mortgage calculator. If you still pay mortgage insurance, the PMI calculator shows when it ends. For the full prepay versus invest debate, read paying off your mortgage early vs investing.
Frequently Asked Questions
How much faster will extra payments pay off my mortgage?
Every extra dollar goes straight to principal, so it stops interest from building on that dollar for the rest of the loan. On a $300,000 balance at 6.5% with 25 years left, an extra $300 a month saves $91,174 in interest and finishes the loan 6 years 5 months early. The calculator counts the exact number of payments, so the time saved is shown in years and months.
How much extra do I need to pay to be mortgage-free by a certain date?
Choose "Pay off by a target date" and enter the time you want left on the loan. The extra amount is the level payment that clears today's balance over that period, minus your current payment. For the same $300,000 at 6.5%, paying it off in 15 years instead of 25 takes about $588 more each month.
Is it better to pay off my mortgage early or invest the money?
It comes down to your mortgage rate against the after-tax return you expect from investing, and how much certainty you want. Paying down a 6.5% mortgage earns a guaranteed 6.5% by avoiding interest. Investing may earn more over long periods, but returns are not guaranteed and can be negative for years. The side panel compares both using the return you enter, before taxes.
Is a lump sum or extra monthly payments better?
Money paid sooner saves more interest, so a lump sum today beats the same total spread over later months. If you do not have a lump sum, steady monthly extras are the next best thing and are easier to keep up. Both lower the balance; neither lowers your required monthly payment unless you ask your lender to recast the loan.
Will my lender charge a penalty for paying off early?
Most mortgages made today have no prepayment penalty, and where one exists it usually applies only in the first few years and often only when you pay off the whole loan. Check your note or closing disclosure, and ask your servicer to apply extra amounts to principal.
What should I do before paying extra on my mortgage?
Common priorities first: an emergency fund, any employer 401(k) match, and paying off higher-rate debt such as credit cards. Extra mortgage payments are hard to get back out without selling or borrowing against the home, so keep enough cash on hand.