Trust
Editorial policy
How we choose, build, check and correct our calculators and the explanations around them.
Independence
Calculator results are never changed for commercial reasons. Advertising, if any, is kept visually separate from tools and results. The site is free and funded by advertising from Google AdSense. Advertisers have no say over which tools we build or what they calculate.
Sources we rely on
- Standards bodies for unit definitions (for example NIST’s exact definitions such as 1 inch = 2.54 cm).
- Official government publications for tax, labor and benefit rules, with the year stated.
- Peer-reviewed research or clinical guidelines for health formulas.
- Manufacturer specifications where a figure depends on a product (for example concrete bag yields), labeled as typical values.
Writing standards
We write for people without a technical background. Every page states what the tool does, how to use it, the formula, a worked example, assumptions and limits. We avoid filler and keyword stuffing.
Review levels
| Tool type | Review before publishing |
|---|---|
| Unit conversions, date math | Formula and test review by an editor |
| Math, statistics, science | Subject editor checks formulas and examples |
| Finance, tax, labor law (YMYL) | Qualified finance reviewer; re-reviewed each tax year |
| Health, pregnancy, medication (YMYL) | Licensed clinician; scope limits on page |
Corrections
Report problems through Report a calculation error. When we fix a significant error, the tool page shows a dated correction note.