About BMI Calculator
BMI Calculator is a free collection of health and fitness calculators and plain-English guides, built to help people understand their numbers and make informed decisions.
Our mission
We believe basic health metrics - your BMI, calorie needs, body fat, and more - should be easy to calculate and easy to understand, without sign-ups, paywalls, or confusing jargon. Every tool runs free in your browser, and every guide is written to be genuinely useful rather than padded with filler.
How we build our calculators
Each calculator uses established, published formulas - for example the Mifflin-St Jeor and Harris-Benedict equations for metabolic rate, the U.S. Navy circumference method for body fat, the Boer formula for lean body mass, and the WHO and Chinese/Asian BMI classification standards. We show the formulas and assumptions so you understand what the numbers mean and where they fall short.
Our sources
Our calculators and articles are based on guidance from recognized public-health and scientific bodies, including the World Health Organization (WHO), the U.S. Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and peer-reviewed research. We aim to reflect mainstream, evidence-based consensus rather than trends or fads.
How we keep content accurate
This is an independent site, not a medical organisation, and we do not employ clinicians. Articles are compiled from the public-health sources named above and checked against them before publishing, and each guide links its main sources at the end. Health guidance changes over time, so if you spot anything out of date or incorrect, email us at [email protected] and we will correct it.
Important medical note
BMI Calculator provides general information and educational estimates only. It is not medical advice and does not replace consultation with a qualified healthcare professional. Please see our Medical Disclaimer for the full details.
How we are funded
This site is free to use and supported by advertising (Google AdSense). Advertising does not influence the health information or recommendations in our calculators and guides - our content decisions are independent of advertisers. See our Privacy Policy for how ads and data work.
Contact
Questions, corrections, and feedback are welcome at [email protected]. We read every message and use it to improve the tools and guides.