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Finance, health, math and conversion calculators built with real formulas. Results appear as you type. Nothing saved. Nothing sent.
Every calculator is free, works instantly, and runs on any device.
The tools people reach for every day.
Built on one idea: every calculation should just work, for free, without fuss.
Numbers alone don't tell the whole story. Every result comes with a chart that shows where your number sits in context: so you walk away actually understanding it.
Generate a polished report the moment you calculate. Share your loan breakdown with a dealer, your BMI with your GP, or your carbon report with your employer.
Every calculation runs inside your browser. Nothing is transmitted to our servers. We collect no personal data and require no account of any kind.
Results update as you type. No submit buttons, no loading spinners, no waiting. Works on any screen from a desktop monitor to an old phone.
Every formula is cross-referenced with WHO, CDC, NIH and standard actuarial references. Sources are cited on each page. No estimates, no shortcuts.
Every calculator page is print-optimised. Hit Ctrl+P and the ads, navigation and decorations disappear: leaving just the results you need on the page.
Every formula on FCALCULATOR.com is sourced from peer-reviewed research and authoritative organisations: the World Health Organization (WHO), the U.S. Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and established actuarial standards for financial tools. Sources are cited on each individual calculator page.
Our editorial team reviews and updates every calculator at least once per year. If you spot an error or have a suggestion, please contact us directly.
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