Our Methodology
How Calculators Are Built
- Formula sourcing. Every formula is sourced from a primary authority (.gov, .edu, or a recognized professional organization) before implementation begins.
- Implementation. All calculation logic is written as pure TypeScript functions with no UI dependencies, making them independently testable.
- Automated testing. Every calculator includes automated tests with values cross-checked against at least two external reference tools (e.g., Bankrate, CFPB, WHO tables).
- Edge case validation. Each function is tested for zero inputs, negative values, very large numbers, and non-numeric inputs to ensure graceful handling.
How Formulas Are Verified
Before publishing, each calculator's output is manually compared against:
- The primary source formula (CDC, NIH, CFPB, IRS, USDA, etc.)
- At least one independent third-party calculator
- Manual calculation using the stated formula
Any discrepancy beyond rounding tolerance is investigated and corrected before launch.
Review Schedule
All calculators display a "last reviewed" date. We review calculators when:
- An authoritative source updates the underlying formula or reference values
- A user reports a potential error
- Routine review cycles (quarterly for YMYL content)
How to Report an Error
Every calculator page has a "Report an error" link. Clicking it opens an email to contact@calqpro.com pre-filled with the page name. Please include the inputs you used and the correct result with a source link. We investigate all reports and typically respond within 2 business days.
Authoritative Sources We Use
- Health / BMI / Nutrition: CDC, NIH, WHO, USDA Dietary Guidelines
- Finance / Mortgage: CFPB, IRS publications, Federal Reserve
- Math / Science: NIST, Khan Academy verified references
- Construction: Industry standard tables and manufacturers' specifications