Editorial Policy

notAcalculator is built by a small, independent team. We are developers and researchers, not a large publishing house or academic institution. We do not employ PhDs or certified financial advisors, and we do not claim to offer professional advice.

What we do offer is a rigorous commitment to accuracy through transparent sourcing. Every calculator and guide on this site includes a References section that cites authoritative primary sources for its data. We believe transparency is more valuable than credentials — you should not have to trust us; you should be able to verify us.

Every calculator begins with research. For each topic, we identify the authoritative primary source:

• Financial calculators: IRS publications (e.g., IRS Publication 936 for mortgage interest), SEC regulations, Federal Reserve guidelines, and standard actuarial methods from the Society of Actuaries.
• Health & fitness calculators: CDC growth charts, WHO growth standards, NIH clinical guidelines, and peer-reviewed medical literature indexed on PubMed.
• Math calculators: ISO standards (ISO 80000 for units and quantities), NIST reference materials, and established mathematical conventions.
• Other calculators: Industry-specific standards from authoritative bodies (e.g., NIST for unit conversions, IUPAC for chemistry).

We never use calculator aggregators, competing calculator sites, or user-generated content platforms (e.g., Wikipedia) as primary sources. When Wikipedia is useful for explanation, we cite the original source listed in their references instead.

Verification happens at multiple stages:

1. Formula extraction: The formula is extracted from the primary source and transcribed into LaTeX and then into JavaScript/TypeScript.
2. Cross-validation: The calculator is tested against known values from the source. For example, if an IRS publication provides a table of example calculations, we verify our calculator produces identical results for those inputs.
3. Edge case testing: We test with boundary values — zero inputs, maximum inputs, negative numbers where applicable — to ensure the calculator fails gracefully or produces sensible results.
4. Automated test suite: Every calculator has automated tests that run before each deployment. A regression cannot reach production without being caught.
5. Source citation: Every reference in the References section links directly to the original source document, not to an intermediary.

Mathematical formulas rarely change, but financial regulations and health guidelines are updated periodically. Our policy:

• Each calculator page displays its last review date. When a source updates its guidelines, we update the corresponding calculator.
• If a user reports an error, we investigate within 48 hours. If confirmed, we deploy a fix and note the correction.
• Significant formula changes are documented in our project changelog.
• We review high-traffic calculators quarterly. Lower-traffic calculators are reviewed on a rolling basis.

We believe the best substitute for institutional authority is radical transparency in sourcing. You should not have to take our word for a formula — you should be able to trace it to its original source and verify it yourself.

Every calculator page includes a References section with direct links to the authoritative documents that define each formula. If you find an error or a discrepancy, you can report it through our contact page, and we will investigate and respond.