Fitness and Health Calculators

Measure, track, and understand your body with calculators built on published biometric formulas. This directory collects our fitness and health tools: BMI and body fat percentages, basal metabolic rate and total daily energy expenditure, calorie and macronutrient targets, ideal weight and pace, heart-rate zones, water intake, pregnancy dating, and due dates. Each calculator names the equation it uses — Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, or the U.S. Centers for Disease Control growth references — and explains where its activity and body-comparison factors come from, so you know which standard a result is measured against. Results are estimates for general information, not medical advice, and should be read alongside guidance from a qualified clinician.