Health & Fitness Calculators

Evidence-based formulas used by clinicians and coaches, explained in plain language. Results are estimates — not medical advice.

  • 8 tested calculators
  • Formulas explained
  • Private and free

Know your numbers

Body mass index, calorie needs and body fat are simple numbers that help you set realistic goals and track progress. Each calculator explains the formula it uses — such as Mifflin-St Jeor for metabolism and the U.S. Navy method for body fat — along with its limitations, so you know how much weight to give the result.

These tools are for general information for healthy adults and are not a substitute for professional medical advice. Talk to your doctor before making significant changes to your diet or exercise.