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Finance & LoansGenerated accuracy model review: 2026-05-06
ROI 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
- The basic formula for ROI is: **ROI = (Net Profit / Cost of Investment) × 100** Where *Net Profit = Amount Returned - Amount Invested*. For **Annualized ROI**, the formula handles the time period: **[(Ending Value / Beginning Value) ^ (1 / Years)] - 1**.
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Amount Invested: $1,000
- Amount Returned: $1,500
- Investment Period: 1 Years
Expected outputs
- ROI: 50.00%
- Annualized ROI: 50.00%
- Net Profit: $500.00
Known limitations
- Does not account for inflation or tax implications of capital gains.
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
- Amount Invested accepts values in $.
- Amount Returned accepts values in $.
- Investment Period accepts values in Years.
- ROI is displayed as a percentage.
- Annualized ROI is displayed as a percentage.
- Net Profit 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.
- Percent outputs are displayed with two decimal places.
Version history
1.0.0 - 2026-05-06
Generated accuracy and testing page from the current roi-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for ROI Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.