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Home & UtilitiesGenerated accuracy model review: 2026-05-06

Mortgage Recast Calculator accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • Monthly payment uses the standard amortization formula before and after subtracting the lump-sum principal payment.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • Current Balance: $350,000
  • Lump-Sum Principal Payment: $50,000
  • Interest Rate: 6.25%
  • Remaining Term: 25 years

Expected outputs

  • Estimated Monthly Savings: $329.83
  • Current Payment: $2,308.84
  • Recast Payment: $1,979.01
  • Recast Balance: $300,000.00

Known limitations

  • This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
  • Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

  • All prices, rates, taxes, and usage values are entered by the user.
  • Calculations run locally in your browser and are not stored by Calwarden.
  • This is planning math, not financial, tax, engineering, or legal advice.

Unit handling

  • Current Balance accepts values in $.
  • Lump-Sum Principal Payment accepts values in $.
  • Interest Rate accepts values in %.
  • Remaining Term accepts values in years.
  • Estimated Monthly Savings is displayed as currency.
  • Current Payment is displayed as currency.
  • Recast Payment is displayed as currency.
  • Recast Balance is displayed as currency.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Currency outputs are displayed with standard US dollar formatting.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current mortgage-recast-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Mortgage Recast Calculator.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

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