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Finance & LoansGenerated accuracy model review: 2026-05-06
Simple Interest 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 formula for simple interest is **I = P × r × t**. * **P** = Principal * **r** = Annual Interest Rate (decimal) * **t** = Time in years
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Principal: $1,000
- Annual Rate: 5%
- Time (Years): 3
Expected outputs
- Total Interest Earned: $150.00
- Total Amount: $1,150.00
Known limitations
- Does not account for compounding periods. For savings accounts or mortgages, use the Compound Interest calculator.
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
- Principal accepts values in $.
- Annual Rate accepts values in %.
- Time (Years) accepts numeric values.
- Total Interest Earned is displayed as currency.
- Total Amount 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 simple-interest-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for Simple Interest.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.