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Everyday LifeGenerated accuracy model review: 2026-05-06
Discount 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
- 1. **Discount Amount** = Original Price × (Discount% / 100) 2. **Price After Discount** = Original Price - Discount Amount 3. **Tax Amount** = Price After Discount × (Tax% / 100) 4. **Final Price** = Price After Discount + Tax Amount
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Original Price: $100
- Discount: 20%
- Sales Tax: 0%
Expected outputs
- Final Price: $80.00
- You Save: $20.00
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
- The discount is applied to the original listed price.
- Sales tax is calculated on the discounted price, not the original price.
- This does not model stacked coupons or store-specific promotion rules.
Unit handling
- Original Price accepts values in $.
- Discount accepts values in %.
- Sales Tax accepts values in %.
- Final Price is displayed as currency.
- You Save 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 discount-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for Discount Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.