Free Health & Fitness Calculators
Instant results for BMI, body fat %, daily calories, ideal weight, and macro splits. Metric and imperial units supported. All calculators are free with PDF export.
Popular Calculators
Choose from our suite of health and fitness calculators. Each provides instant, accurate results with detailed explanations and the option to download your results as a PDF.
BMI Calculator
Check your Body Mass Index (BMI) using metric or imperial units.
Daily Calorie Needs (BMR/TDEE)
Estimate daily calories burned at rest (BMR) and total daily energy expenditure (TDEE).
Body Fat % Calculator
Estimate body fat % using circumference-based methods.
Ideal Weight Calculator
Compare multiple formulas (Devine, Robinson, Miller) for 'ideal' body weight ranges.
Macro Split Calculator
Get daily grams of protein, carbs, and fat based on calorie target and goal.
How It Works
Getting your health metrics has never been easier. Our calculators are designed to be simple, fast, and accurate—no registration or downloads required.
Enter Your Measurements
Choose your preferred unit system—metric or imperial—and enter your measurements. Each calculator clearly labels what's needed, whether that's your height and weight for BMI, circumference measurements for body fat, or your calorie target for macro splits. Your inputs are saved locally in your browser so you can easily return and recalculate without re-entering everything.
Get Instant Results
Click Calculate and see your results immediately. Every calculator uses established, peer-reviewed formulas: the standard BMI formula endorsed by the WHO, the Mifflin-St Jeor equation for BMR, the US Navy method for body fat, and the Devine, Robinson, and Miller formulas for ideal weight. Results include your score, category, and a plain-language explanation of what the numbers mean for your health.
Learn and Take Action
Below every calculator you'll find detailed educational content explaining how to interpret your results, what factors affect your metrics, and common mistakes to avoid. Download your results as a PDF to share with a healthcare provider, or browse our library of guides and worked examples to deepen your understanding. Each calculator also links to related tools so you can build a complete picture of your health.
Why Use Our Calculators?
Our tools are built with accuracy, privacy, and ease of use in mind. Here's what sets us apart from other online health calculators.
Accurate Formulas
Every calculator uses peer-reviewed, medically established formulas. We use the Mifflin-St Jeor equation for BMR, the WHO-standard BMI formula, and the US Navy method for body fat—the same formulas used by healthcare professionals worldwide.
Instant Results
Get immediate calculations with detailed breakdowns. No waiting, no loading screens, and no registration required. Enter your measurements and click Calculate to see your results in under a second.
100% Private
Your health data stays on your device. All calculations happen in your browser—we never send your measurements to any server. Your inputs are saved locally so you can recalculate easily, and you can clear them at any time.
PDF Export
Download your results as a clean, professional PDF. Perfect for sharing with your doctor, personal trainer, or nutritionist. Each PDF includes your inputs, results, and a disclaimer so it's ready to discuss with a professional.
Ready to Get Started?
Choose a calculator above and get your results in seconds. All tools are free and respect your privacy—no registration, no data collection, no hidden fees.
Important: All calculators on this site are for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making health decisions. Results are estimates based on standard formulas.