About EveryCalculator

EveryCalculator publishes calculation tools that show their work. Most calculator sites give you a number; we also give you the formula, the convention behind it, the edge cases that break it, and a citation you can check.

Why the site exists

Nearly every calculation that goes wrong in practice goes wrong for one of a small number of reasons: an ambiguous convention, a unit assumption nobody stated, or a formula applied outside the range it was derived for. A tool that only returns a number cannot help you spot any of those.

So each page here documents the method rather than hiding it. If a date calculation clamps 31 January to 28 February, the page says so and explains why. If BMI misclassifies muscular people, the page says that too, instead of presenting a category as a verdict.

How pages are written

• Primary sources. Unit definitions come from BIPM and NIST, date rules from ISO 8601, health reference values from WHO and EFSA. We cite the standard, not a summary of it.
• Stated conventions. Where more than one defensible answer exists - inclusive versus exclusive day counting, month-end clamping, US versus imperial gallons - the page names the convention it follows.
• Worked examples with intermediate steps. Realistic figures, shown at each stage, because that is where manual errors become visible.
• Documented limits. Every page states what its method cannot tell you. A calculator that never admits uncertainty is misleading by omission.
• Review dates. Each page carries the date it was last checked against its sources.

What we deliberately do not do

We do not require an account, and we do not want one. Calculator inputs are not stored and are not linked to you; most calculations never leave your browser. We do not run analytics of our own, we do not fingerprint visitors, and we do not sell data. The Privacy Policy sets out precisely what is processed.

How the site is funded

Advertising, through Google AdSense, and nothing else. There is no paid tier, no affiliate marketing, and no sponsored placement inside the explanatory content. Ads are clearly separated from editorial text, and where consent has not been given they are served non-personalised. Being explicit about this matters: a reader should know what the incentive behind a page is.

Languages

The site is available in English, Turkish, German, and Spanish on separate subdomains, with URLs localised in each language. English is the most complete; the other languages currently carry the calculators and interface but not yet the full written explanations, and they are excluded from search indexing until that content is genuinely written rather than translated mechanically.

Corrections

If you find an error in a formula, a factor, or an explanation, please report it through the contact form. Corrections are made promptly and the review date on the affected page is updated. Reports that identify a specific figure and the source it should match are the most useful.