Our Mission
SmartFitCalcs provides free, accurate, and easy-to-use health & fitness calculators to help people make informed decisions about their wellbeing.
What We Offer
- Free calculators — every tool is free, no sign-up required
- Up-to-date methods — Mifflin-St Jeor, US Navy body fat, Karvonen heart-rate, Riegel race prediction, and more
- Educational content — in-depth guides that explain the math behind the numbers
- Mobile-friendly — built mobile-first with fast, real-time calculations
Our Standards
- Accuracy — all calculations are based on established, peer-reviewed formulas
- Transparency — every tool shows its method and its source
- Privacy — calculator inputs are processed in your browser and never stored. See our Privacy Policy
Sources We Use
- World Health Organization (WHO) — BMI classification
- Mifflin-St Jeor (1990) and revised Harris-Benedict (Roza & Shizgal, 1984) — BMR
- U.S. Navy circumference method — body fat percentage
- Tanaka et al. (2001) and Karvonen — heart-rate zones
- Riegel (1981) — race-time prediction
- Epley, Brzycki, Lombardi — 1RM estimation
- CDC growth charts — children's BMI percentiles
Important Disclaimer
Our calculators are educational tools, not medical advice. Please read our full Disclaimer and consult a qualified healthcare or fitness professional for decisions about your health.
Contact Us
Have feedback, a question, or a tool request? Please use our contact form.