Extra mortgage payment calculator
See how much interest you save, how many years you cut and your new payoff date when you pay extra on a mortgage. The example below is already filled in; replace it with your own numbers.
What an extra payment does to your mortgage
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On a new $300,000, 30-year mortgage at 6.5%, paying an extra $200 a month saves about $103,449 in interest and ends the loan 6 years and 11 months early. The earlier you start and the larger the extra payment, the more you save.
What you need to use the calculator
- Loan balance: the principal you still owe, from your latest mortgage statement.
- Annual interest rate: the rate on your note. This is the interest rate, not the APR.
- Remaining term: the years left on the loan (for example, 25 if you are five years into a 30-year loan).
- Extra payment: a monthly amount, a yearly amount, or a one-time payment on a date you choose.
The calculator covers principal and interest only. Property taxes, homeowners insurance and mortgage insurance are not included, so leave them out of the balance and the payment.
Monthly, yearly or one-time: which saves more?
Same loan in every row: a new $300,000 mortgage at a 6.5% fixed rate for 30 years. The scheduled payment is $1,896.20.
| Extra payment | Interest saved | Time saved | New payoff time |
|---|---|---|---|
| +$200 every month | $103,449 | 6 yr 11 mo | 23 yr 1 mo |
| $2,400 once a year (December) | $99,670 | 6 yr 9 mo | 23 yr 3 mo |
| $10,000 once, in month 13 | $49,931 | 2 yr 7 mo | 27 yr 5 mo |
| $10,000 once, in month 61 | $37,116 | 2 yr | 28 yr |
The first two rows add up to the same $2,400 a year; the last two use the same $10,000. Extra amounts are applied to principal in the month shown. Method: How the calculator works.
Two patterns stand out. Spreading the same money across the year beats one payment in December, because it reaches the balance sooner. And the same $10,000 saves about $12,800 more when it arrives in year 2 than in year 6. For more detail, read One extra mortgage payment a year and What happens if you pay an extra $200 a month.
A mortgage you have been paying for years
Most people use a calculator on a loan they already have. Here the loan has $250,000 left at 6.5% with 25 years remaining. The scheduled payment is $1,688.02 and the total interest still to come is $256,405.
| Extra per month | Interest saved | Time saved | New payoff time |
|---|---|---|---|
| +$100 | $37,671 | 3 yr 1 mo | 21 yr 11 mo |
| +$200 | $64,928 | 5 yr 6 mo | 19 yr 6 mo |
| +$300 | $85,737 | 7 yr 4 mo | 17 yr 8 mo |
| +$500 | $115,668 | 10 yr 1 mo | 14 yr 11 mo |
Assumptions: $250,000 balance, 6.5% fixed rate, 25 years remaining, extra amount applied to principal every month from the next payment.
Why the same $200 saves less on a shorter loan
The savings depend on how much time the money has to work. Take the same $250,000 balance at 6.5% and add $200 a month:
| Years remaining | Scheduled payment | Interest saved | Time saved |
|---|---|---|---|
| 25 years | $1,688.02 | $64,928 | 5 yr 6 mo |
| 20 years | $1,863.93 | $39,514 | 3 yr 6 mo |
| 15 years | $2,177.77 | $21,016 | 1 yr 11 mo |
| 10 years | $2,838.70 | $8,795 | 10 mo |
$250,000 balance, 6.5% fixed rate, +$200 a month applied to principal from the next payment.
This is not a reason to wait: on a loan with 25 years left, every month you delay gives up part of the savings. It is a reminder that a shorter loan already pays interest off faster, so the extra money matters less.
Check these things before you pay extra
- Prepayment penalty. The CFPB says penalties do not normally apply if you pay extra principal in small chunks, but it recommends confirming with your lender. See Prepayment penalty: what it is and how to check yours.
- Make sure it goes to principal. Ask your servicer how to designate an extra payment as principal-only, and check on your next statement that the balance dropped by the extra amount.
- Your monthly payment stays the same. Extra payments normally shorten the loan rather than lower the payment. Some lenders offer to recalculate the payment after a large principal payment; availability, minimums and fees vary, so ask your servicer.
- Debt at a higher rate and your safety net. If another debt costs more than your mortgage, paying that one first generally avoids more interest. Money sent to a mortgage is hard to get back, so keep an emergency fund first.
Want to see every payment? The amortization calculator with extra payments shows the full schedule, split into interest and principal.
Frequently asked questions
How does an extra mortgage payment calculator work?
How much does an extra $200 a month save on a mortgage?
Is it better to pay extra every month or once a year?
Will extra payments lower my monthly mortgage payment?
Can I be charged a penalty for paying extra on my mortgage?
Sources
- Consumer Financial Protection Bureau, What is a prepayment penalty? (reviewed September 11, 2024).
- All figures were calculated with the Financial Accelerator engine; the formulas and assumptions are public in How the calculator works. Other calculators can show slightly different results depending on when they credit the extra payment.
This page is educational and not financial, legal or tax advice. Estimates assume a fixed rate and that extra money is applied to principal. Confirm the terms of your own loan with your servicer.