Health Calculators

They use the equations that clinicians and researchers trust — WHO thresholds for BMI, Mifflin-St Jeor for metabolic rate, the U.S. Navy method for body fat — so at the population level they correlate well with the outcomes they estimate. For any single person, results are approximations, because the formulas are built from averages and cannot see your exact body composition, genetics or health history. They are an excellent starting point and a good way to track change, not a precise personal measurement.

No, and they are not intended to. Every health tool here provides general information based on published formulas, which is different from a clinical assessment that accounts for your full history, medications and lab results. Use the numbers to frame questions and track trends, then bring them to a doctor or registered dietitian for interpretation. That matters most before making significant changes to diet, exercise or weight, where individual circumstances genuinely change the right advice.

BMI follows the World Health Organization's adult categories; BMR and the calorie and TDEE tools use the Mifflin-St Jeor equation, widely regarded as the most accurate prediction equation for resting metabolism; and body fat uses the U.S. Navy circumference method. Each calculator names and links its source so you can read the original research. Choosing well-validated equations is the single biggest factor in getting a trustworthy estimate, which is why these are the standards we implement.