Free Health Calculators

Estimate BMI, daily calorie needs, body fat and water intake. These calculators use standard published formulas and are for general information only, not medical advice.

• BMI calculator – BMI = weight in kg ÷ (height in m)². Under 18.5 is underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, 30 or more obese.
• BMR calculator – Mifflin-St Jeor: 10 × kg + 6.25 × cm − 5 × age, then +5 for men or −161 for women.
• Calorie (TDEE) calculator – TDEE = BMR × an activity factor from 1.2 (sedentary) to 1.9 (very active).
• Ideal Weight calculator – Devine formula: 50 kg (men) or 45.5 kg (women) plus 2.3 kg for each inch of height above 5 feet.
• Body Fat (US Navy) calculator – The US Navy method estimates body fat from height, neck and waist (plus hip for women) measurements using logarithms.
• Water Intake calculator – A common guide is about 33 ml of water per kg of body weight per day.