Calwarden
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Finance & LoansGenerated accuracy model review: 2026-05-06

College Cost 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

  • The calculator uses the Future Value formula to inflate the current cost of tuition for the number of years until college starts. It then calculates the cost for each subsequent year of the degree (compounding inflation further). Finally, it uses the Sinking Fund formula (PMT) to determine the monthly savings required to reach that total sum, assuming a modest investment return.

Test cases

Default input regression check

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

Inputs

  • Current Annual Cost: $25,000
  • Years until College: 10 Years
  • College Inflation: 5%
  • Degree Duration: 4 Years

Expected outputs

  • Projected Total Cost: $175,518.49
  • Cost Freshman Year: $40,722.37
  • Monthly Savings Need: $1,071.02

Known limitations

  • Assumes a fixed investment return of 6% for the savings calculation. Actual market returns vary.

Assumptions

  • Inputs are interpreted exactly as entered in the calculator form.
  • The calculation runs locally in the browser using the current checked-in calculator definition.

Unit handling

  • Current Annual Cost accepts values in $.
  • Years until College accepts values in Years.
  • College Inflation accepts values in %.
  • Degree Duration accepts values in Years.
  • Projected Total Cost is displayed as currency.
  • Cost Freshman Year is displayed as currency.
  • Monthly Savings Need 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.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current college-cost-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for College Cost.

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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