❤️About Health & Fitness Calculators
Whether you're a gym-goer tracking body fat percentage, a runner calculating your optimal heart rate training zones, or someone who just wants to know their healthy weight range before a doctor's appointment — these health calculators use the same clinically validated formulas that healthcare professionals rely on.
Start with the BMI Calculator for a quick health screening, or go deeper with the Body Fat Calculator (Navy circumference method) if you want to separate fat mass from muscle. The Calorie & TDEE Calculator is the right starting point for any weight loss or muscle gain plan — it calculates your exact daily calorie needs based on your activity level.
Every formula is sourced from peer-reviewed medical research: Mifflin-St Jeor for BMR (the most accurate equation for non-athletes), WHO-adjusted thresholds for South and East Asian BMI classification, and the Karvonen method for heart rate zones. The women's health tools — period tracker, ovulation calculator, and fertility window predictor — run entirely offline. Not one byte of your health data is ever transmitted to any server.