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Property calculators

Extra Mortgage Payment Calculator

Estimate how extra mortgage payments could change payoff time and total interest if the extra money is applied to principal.

Extra mortgage payment inputs

Mortgage and extra payment

Current balance, rate, remaining term, regular payment and optional extra monthly amount.

$
%
years
$
$

Optional monthly amount, assuming it is applied to principal.

Result updated. Estimated interest saved $64,514.

Estimated interest saved

$64,514

Faster payoff

Extra payments are estimated to shorten the payoff time and reduce interest if they are applied to principal.

New payoff time
20 years, 2 months
New payoff date
March 2046

Key takeaway

With the extra payments entered, the mortgage is estimated to be paid off 3 years, 11 months sooner and save about $64,514 in interest.

One-off payment and date labelsAdd a one-time payment and choose the start month for payoff-date labels.
$

Optional one-time amount, assuming it is applied to principal.

Month 1 means the first month in the estimate.

Region and currencyChanges defaults and currency formatting only.

Region settings change defaults and formatting only. They do not convert currencies or provide mortgage advice. US defaults use USD formatting.

Payoff comparison

Current schedule compared with the extra-payment estimate.

Current schedule payoff time
24 years, 1 month
Current schedule payoff date
February 2050
Current schedule interest
$343,212
Extra-payment payoff time
20 years, 2 months
Extra-payment payoff date
March 2046
Extra-payment interest
$278,698
Time saved
3 years, 11 months
Interest saved
$64,514

Key payoff metrics

Estimated time, date and interest changes.

Current payoff time
24 years, 1 month
New payoff time
20 years, 2 months
Time saved
3 years, 11 months
Interest saved
$64,514
Total extra paid
$48,200
New payoff date
March 2046
Annual payoff summaryA compact yearly view of the extra-payment schedule.
Year 1$2,400 extra paid that year.
$22,494 interest, $341,294 remaining
Year 2$2,400 extra paid that year.
$21,911 interest, $332,004 remaining
Year 3$2,400 extra paid that year.
$21,288 interest, $322,093 remaining
Year 4$2,400 extra paid that year.
$20,625 interest, $311,517 remaining
Year 5$2,400 extra paid that year.
$19,916 interest, $300,234 remaining
Year 6$2,400 extra paid that year.
$19,161 interest, $288,194 remaining
Year 7$2,400 extra paid that year.
$18,354 interest, $275,349 remaining
Year 8$2,400 extra paid that year.
$17,494 interest, $261,643 remaining
Year 9$2,400 extra paid that year.
$16,576 interest, $247,019 remaining
Year 10$2,400 extra paid that year.
$15,597 interest, $231,416 remaining

Warnings to note

  • Actual payoff quotes can differ because of daily interest, fees, timing and payment allocation rules.
  • The calculated payoff time differs from the remaining term entered. Check whether the balance, rate and payment match the current mortgage.
  • Lender prepayment rules can vary. Extra payments may need to be marked for principal to match this estimate.

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General estimate only

This calculator provides general estimates only. It is not financial, tax, legal, accounting, mortgage or lending advice. It assumes extra payments are applied to principal and does not include prepayment penalties, offset accounts, redraw features, taxes or lender-specific payment rules.

How this extra mortgage payment calculator works

The calculator builds a current payoff schedule from the loan balance, interest rate and monthly payment. It then builds a second schedule with the extra monthly payment and any one-off payment entered.

How extra payments can reduce interest

If extra payments are applied to principal, the balance falls sooner. A lower balance can reduce future interest, which may shorten the estimated payoff time.

Current schedule vs extra-payment schedule

The comparison shows the estimated payoff time, payoff date, total interest and total paid for both schedules. Remaining term is used as a sense check, but the schedule is calculated from balance, rate and payment.

Why lender payment rules matter

Some lenders apply extra payments differently or require instructions for principal-only payments. Actual payoff quotes can also differ because of daily interest, fees and timing.

What this calculator does not include

This calculator does not include prepayment penalties, tax effects, lender-specific allocation rules, offset or redraw accounts, refinance decisions, daily interest or official payoff quotes.

Key terms and assumptions

  • Principal application: Extra payments are assumed to reduce principal after monthly interest is applied.
  • Current schedule: The current payoff schedule is calculated from balance, interest rate and monthly payment.
  • One-off payment: A one-off payment is applied in the month entered and capped to the remaining balance.
  • Payoff date: The payoff date label uses the start month and year entered. It is an estimate, not an official payoff quote.
  • Lender rules: Actual results can differ if a lender applies extra payments differently or charges fees.
  • General estimate: The calculator excludes tax effects, prepayment penalties, offset accounts, redraw features and lender-specific payoff rules.

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FAQs

How do extra mortgage payments save interest?

If applied to principal, extra payments reduce the balance that future interest is charged on.

Does this assume extra payments go to principal?

Yes. The estimate assumes extra amounts are applied to principal after monthly interest.

What if my lender applies payments differently?

Your actual result may differ. Check lender rules and payoff statements.

Can I include a one-off extra payment?

Yes. Use the advanced one-off payment field and choose the payment month.

What if my current payment does not cover interest?

The calculator will warn that the loan would not pay down under those assumptions.

Does this include prepayment penalties?

No. It does not include penalties, fees, tax effects, offset accounts or redraw features.

Why does the entered remaining term matter?

It helps explain the current schedule, but the payoff estimate is based on balance, rate and payment.

Can I use this outside the United States?

Yes. Region settings change formatting and labels only.