Calculator methodology and testing policy.
Fair Calcs publishes planning estimates, not guaranteed outcomes. This policy explains how formulas, changing external assumptions, browser behavior, and corrections are handled.
Formula validation
- Use standard published formulas or clearly described arithmetic.
- Keep full precision during calculations and round only for display unless cent-level solver logic requires otherwise.
- Check known-value examples, zero-rate cases, invalid inputs, and practical upper and lower boundaries.
- For minimum-price solvers, verify that the returned cent satisfies the target and the previous cent does not.
- Run browser checks across every generated calculator route and narrow mobile layouts.
External rates and marketplace rules
Marketplace fees and other changing rules require an official source, a visible review date, and a limitation explaining where the estimate may differ. Fair Calcs does not silently present a changing rate as permanent.
Automation and editorial review
Reusable code generates consistent page structure, validation, and metadata. Each published calculator still requires a working formula, editable inputs, page-specific limitations, and automated checks. Dates are changed only when formulas, sources, or editorial content are materially reviewed.
Privacy and corrections
Static calculator inputs remain in the browser unless a page explicitly says otherwise. Report a suspected formula or source issue to support@faircalcs.com; corrections are prioritized when they can change a decision.