What is BMI Calculator?

BMI Calculator (bmicalculator.it.com) is a free online health tool website providing instant, accurate, and easy-to-use health calculators and converters. Our tools include a Body Mass Index (BMI) Calculator, Calorie Calculator, Ideal Weight Calculator, Body Fat Calculator, and Unit Converter — all available with no registration, no fees, and no personal data collection.

All calculations run entirely in your browser using JavaScript. Nothing you enter — your age, height, weight, or any other measurement — is ever sent to a server, stored in a database, or shared with any third party. Your privacy is fully protected by design.

🔒 Zero data collection. All calculations are done locally in your browser — your data never leaves your device.

Our Free Tools

Every tool on BMI Calculator is designed to be simple, fast, and accurate — based on internationally recognized formulas from the WHO, CDC, and peer-reviewed medical research.

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BMI Calculator
Metric & US units. Animated gauge, BMI Prime, Ponderal Index, healthy weight range.
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Calorie Calculator
BMR + TDEE using Mifflin-St Jeor equation. 5 activity levels.
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Ideal Weight Calculator
4 medical formulas: Devine, Robinson, Miller, Hamwi + WHO BMI range.
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Body Fat Calculator
US Navy circumference method. Shows fat mass, lean mass, and health category.
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Unit Converter
Length, weight/mass, and temperature. Real-time results as you type.

Our Mission

Our mission is simple: make trusted health information and calculation tools freely accessible to everyone — regardless of location, device, or technical ability. We believe that basic health awareness tools should never be locked behind paywalls or signup walls.

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Instant Results
No loading, no waiting. Results appear immediately as you type.
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Works Everywhere
Fully responsive — phones, tablets, desktops. Any screen size.
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Privacy First
Zero data stored or transmitted. All processing is local.
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Science-Based
WHO, CDC, and peer-reviewed formulas. Accurate and reliable.

Accuracy & Medical Sources

All formulas used in our calculators are based on established medical research and guidelines from internationally recognised health authorities:

  • BMI Formula — World Health Organization (WHO) standard: weight(kg) ÷ height²(m²)
  • BMI Classification — WHO Global Database on Body Mass Index (2025)
  • Calorie Calculator — Mifflin, M.D. et al. (1990), American Journal of Clinical Nutrition
  • Body Fat Calculator — US Navy body fat circumference method (Hodgdon & Beckett, 1984)
  • Ideal Weight Formulas — Devine (1974), Robinson (1983), Miller (1983), Hamwi (1964)
  • Children's BMI — CDC Growth Charts and BMI-for-age percentile standards

Despite using validated formulas, our tools are for informational purposes only and do not constitute medical advice. Please see our Medical Disclaimer for full details.

⚕️ Important Health Disclaimer

The tools and information on this website are for educational and informational purposes only. They are not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making health-related decisions. For the full disclaimer, please visit our Medical Disclaimer page.

Have a Question or Suggestion?

We love hearing from our users. If you have a question about our calculators, a suggestion for a new tool, or found an error, please get in touch. We typically respond within 24 hours.

✉️ Contact Us ← Back to Calculator