Editorial Policy & Methodology
How To Calculate is built to be a practical reference—not just a collection of tools. This page explains how we create calculators, how we choose formulas and assumptions, how we review and update content, and how to request corrections.
What we publish
Methodology standards
- Formula-first: we use standard, widely accepted formulas and define inputs/units clearly.
- Assumptions made explicit: compounding frequency, rounding, timing conventions, fees/taxes where applicable.
- Edge cases: we document situations where the calculation can mislead or fail (e.g., APR vs APY, escrow vs P&I).
- Educational intent: calculators are for planning and “what-if” analysis, not guarantees.
Sources & citation policy
When we reference definitions, rules, or official parameters, we prefer primary sources (government agencies, standards bodies, and reputable institutions). For topic background, we use high-quality secondary sources.
Many calculators include a Sources section. If you find a missing or outdated citation, please contact us.
Review policy
We aim to have calculators reviewed by subject-matter reviewers (e.g., financial planners, physicians, engineers). Some pages show a “Reviewed by” line. Review indicates the methodology was checked, not that the output is personalized advice.
Update cadence
Important pages are refreshed on a schedule so examples, assumptions, and FAQ guidance stay current. We focus on meaningful deltas (examples, assumptions, interpretation) rather than cosmetic changes.
Corrections
If you believe a calculator has an error (formula, unit, or assumption), please contact us with: the page URL, what you expected, and a reference/source if possible.
Contact pageDisclaimers
For important limitations and scope, read our Disclaimers.