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EV & CarsGenerated accuracy model review: 2026-05-06
Car Depreciation 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
- Future value = purchase price x first-year remaining value x annual remaining value for later years.
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Purchase Price: $38,000
- First-Year Depreciation: 18%
- Later Annual Depreciation: 12 %/yr
- Years Owned: 5 years
Expected outputs
- Estimated Depreciation: $19,313.49
- Estimated Future Value: $18,686.51
- Value Retained: 49.18%
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, fees, rates, and vehicle assumptions are user-entered.
- Calculations run locally in your browser and are not stored by Calwarden.
- This is planning math, not financial, tax, insurance, legal, or mechanical advice.
Unit handling
- Purchase Price accepts values in $.
- First-Year Depreciation accepts values in %.
- Later Annual Depreciation accepts values in %/yr.
- Years Owned accepts values in years.
- Estimated Depreciation is displayed as currency.
- Estimated Future Value is displayed as currency.
- Value Retained is displayed as a percentage.
Rounding rules
- Number displays use up to 2 decimal places in the calculator UI.
- Currency outputs are displayed with standard US dollar formatting.
- Percent outputs are displayed with two decimal places.
- Input precision follows configured step values where provided.
Version history
1.0.0 - 2026-05-06
Generated accuracy and testing page from the current car-depreciation-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for Car Depreciation Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.