Calculator 05
Extra Payment Calculator
One-off and recurring overpayments, measured against the interest they save and the months they remove. Illustrative figures only.
Both lines are labelled on the plot; the gap between them at the bottom axis is the time you buy back.
Interest you would not pay
$129,824
Illustrative estimate over the life of the loan.
- Time removed6 yrs 10 mos
- Extra actually paid$69,250
- Saved per extra dollar1.87
- As contracted30 yrs
- With your extra23 yrs 2 mos
- Original payoffSep 2056
- New payoffNov 2049
- Interest as contracted$484,669
- Interest with extra$354,845
Payoff months are counted from today and shown as a month and year. They assume you start this month and never miss the overpayment.
| Month | Payment | Principal | Interest | Interest to date | Balance |
|---|---|---|---|---|---|
| 1 | $2,652 | $594 | $2,058 | $2,058 | $379,406 |
| 2 | $2,652 | $597 | $2,055 | $4,113 | $378,810 |
| 3 | $2,652 | $600 | $2,052 | $6,165 | $378,210 |
| 4 | $2,652 | $603 | $2,049 | $8,214 | $377,607 |
| 5 | $2,652 | $606 | $2,045 | $10,259 | $377,000 |
| 6 | $2,652 | $610 | $2,042 | $12,301 | $376,390 |
| 7 | $2,652 | $613 | $2,039 | $14,340 | $375,777 |
| 8 | $2,652 | $616 | $2,035 | $16,376 | $375,161 |
| 9 | $2,652 | $620 | $2,032 | $18,408 | $374,541 |
| 10 | $2,652 | $623 | $2,029 | $20,437 | $373,918 |
| 11 | $2,652 | $626 | $2,025 | $22,462 | $373,291 |
| 12 | $2,652 | $630 | $2,022 | $24,484 | $372,662 |
| 13 | $2,652 | $633 | $2,019 | $26,503 | $372,028 |
| 14 | $2,652 | $637 | $2,015 | $28,518 | $371,392 |
| 15 | $2,652 | $640 | $2,012 | $30,529 | $370,752 |
| 16 | $2,652 | $644 | $2,008 | $32,538 | $370,108 |
| 17 | $2,652 | $647 | $2,005 | $34,542 | $369,461 |
| 18 | $2,652 | $651 | $2,001 | $36,544 | $368,810 |
| 19 | $2,652 | $654 | $1,998 | $38,541 | $368,156 |
| 20 | $2,652 | $658 | $1,994 | $40,536 | $367,498 |
| 21 | $2,652 | $661 | $1,991 | $42,526 | $366,837 |
| 22 | $2,652 | $665 | $1,987 | $44,513 | $366,172 |
| 23 | $2,652 | $668 | $1,983 | $46,497 | $365,504 |
| 24 | $2,652 | $672 | $1,980 | $48,476 | $364,832 |
Payments 1–24 of 278
Illustrative figures. Every number on this page — including the rates in the default values — is an illustration produced from the inputs above. Nothing here is a quote, a rate lock, an APR, a Loan Estimate or an offer of credit.
What this page assumes. A fixed rate, no prepayment penalty, every extra dollar applied to principal on the day of the scheduled payment, and the overpayment kept up without interruption. Servicers that apply overpayments to the next instalment instead of the balance will not produce this result.
This calculator provides estimates for educational purposes only. Results are not a Loan Estimate, pre-approval, or commitment to lend, and may not reflect taxes, insurance, HOA dues, or other costs. Contact a loan officer for an accurate quote.
Rates shown are for illustrative purposes only, are not a quote or guarantee, and do not reflect a specific offer. Actual rates depend on credit score, loan amount, loan-to-value, occupancy, and other factors, and change daily. Contact us for a personalized rate quote.
Your inputs live in this page’s web address. Copy the link and whoever opens it lands on exactly these numbers — no account, no saved data, nothing tracked.
Have a loan officer look at these numbers
A calculator can only work with what you type. If you would like a person to sanity-check the assumptions, this is the form a real site would use.
The other calculators
All calculators- Monthly paymentMortgage Payment CalculatorPrincipal, interest, tax, insurance, HOA and PMI — itemised.
- AmortisationAmortization ScheduleEvery payment, month-wise or year-wise, with running totals.
- AffordabilityAffordability CalculatorIncome, debts and DTI to a price range — and which limit binds.
- RefinanceRefinance & Break-Even CalculatorNew rate against costs, and the month it pays itself back.
- Rent vs buyRent vs Buy CalculatorOver a holding period, with every assumption on the page.
Calculator FAQ
Questions about overpaying
Why does a small extra payment save so much interest?
Because it never earns interest again. A dollar of extra principal removes that dollar from every future interest calculation for the rest of the loan. On a 30-year mortgage a dollar paid in year one avoids nearly thirty years of compounding, which is why modest recurring overpayments are so much more effective than their size suggests.
Is it better to pay extra every month or one lump sum?
Timing matters more than form. A lump sum paid early beats the same money spread over years, and a recurring payment beats a lump sum you keep postponing. The calculator lets you model both together, so try the version you would actually keep up.
Do I have to tell my servicer the extra is for principal?
Usually yes. Many servicers apply an unexplained overpayment to the next month's bill rather than to the balance, which does you almost no good. Look for a "principal only" option, or send it with written instructions, and check the next statement to make sure it landed where you meant.
Are there prepayment penalties?
On most modern owner-occupied mortgages, no — but they do still exist on some non-QM and investor products. Check your note before you start overpaying. This calculator assumes there is no penalty of any kind.
Should I overpay the mortgage or invest the money instead?
That is a genuine trade-off and this page does not pretend to settle it. Overpaying earns a guaranteed return equal to your mortgage rate, tax-free, with no volatility; investing may earn more but is not guaranteed. Emergency savings and high-interest debt generally come first. The rent versus buy calculator on this site models the opportunity-cost side of the same question.
Does overpaying reduce my monthly payment?
No. On a standard mortgage, extra principal shortens the loan rather than shrinking the payment — the payment stays the same and the schedule just ends sooner. Some servicers offer a "recast" that recalculates the payment on the lower balance, usually for a fee; ask before you assume it is available.
Thinking about paying it down faster?
Sometimes a shorter term beats overpaying a long one. A loan officer can compare both against your actual note.