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Mortgage Extra Payments Calculator

decimal

Result

Calculated result 8.9 Based on the values entered.
↗ Finance

Mortgage Extra Payments Calculator — free online calculator.

Formula

Add extra to each monthly payment, then amortize: Interest = Balance × r, Principal = (M + extra) − Interest
  • Mortgage Extra Payments Calculator calculates its result from Balance, Rate (decimal), Mass, Extra. It uses the formula Add extra to each monthly payment, then amortize: Interest = Balance × r, Principal = (M + extra) − Interest. Change any input to recalculate the result instantly.
  • The main inputs are Balance, Rate, Mass, Extra. Enter them in the units and format shown in the calculator.
  • Use monetary amounts, rates and time periods exactly as labeled; the result reflects the assumptions entered on this page.
  • Changing any input above recalculates the result with the same calculation engine used by this page.

Example: Mortgage Extra Payments

Inputs
  • Balance: 2
  • Rate: 0.05 decimal
  • Mass: 4
  • Extra: 5

Using Balance = 2, Rate (decimal) = 0.05, Mass = 4, Extra = 5, the calculated result is 8.9.

Sample result: Calculating…

Frequently asked questions

What does the Mortgage Extra Payments calculate?

Mortgage Extra Payments Calculator — free online calculator.

Which values should I enter?

Enter Balance, Rate, Mass, Extra using the units and format shown beside each field.

What formula does this calculator use?

The calculator uses the following relationship: Add extra to each monthly payment, then amortize: Interest = Balance × r, Principal = (M + extra) − Interest.

Why might my result differ from another source?

Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.

Does the result update automatically?

Yes. Changing an input updates the result using the same calculation engine shown on this page.

Page information

Updated: October 7, 2026