BMI & Body Health Calculator

Calculate BMI, BMR, TDEE, body fat percentage, ideal weight, water intake, and macros in one free body health dashboard. Instant results, no signup needed.

How to Use BMI & Body Health Calculator

  1. Select your unit system (Imperial or Metric)
  2. Enter your gender, age, height, and weight
  3. Choose your activity level and fitness goal
  4. Click Calculate to see your complete health profile

Frequently Asked Questions

What is BMI and is it accurate?

BMI (Body Mass Index) = weight(kg) ÷ height(m)². Under 18.5 = Underweight, 18.5-24.9 = Normal, 25-29.9 = Overweight, 30+ = Obese. BMI is a simple screening tool — it doesn't account for muscle mass, bone density, or fat distribution. Athletes often have high BMI despite low body fat.

What is BMR and why does it matter?

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to breathe, pump blood, and maintain organs. It's your minimum calorie floor. Total daily calorie needs = BMR × activity factor (1.2-1.9). Our dashboard calculates both.

How do I calculate body fat percentage?

Methods: (1) DEXA scan — most accurate but expensive, (2) Calipers — skin fold measurements, (3) Navy Method — uses neck, waist, and hip measurements. Our dashboard uses the Navy Method formula for a free estimate without equipment.

How much water should I drink per day?

General guideline: 35ml per kg of body weight. A 70kg person needs ~2.45L/day. Adjust for activity level, climate, and health status. Athletes in hot climates may need 3-4L+. Our dashboard calculates your personalized daily target.

What is my ideal body weight?

Several formulas exist: Devine (men: 50kg + 2.3kg per inch over 5ft), Robinson, Miller. Ideal weight ranges vary with frame size. These are statistical averages — your ideal weight depends on your build, muscle mass, and health goals. Use as a rough guide.

How accurate is the calorie needs calculator?

Our calculator uses the Mifflin-St Jeor equation (most validated formula) with activity multipliers. Accuracy is within 10-15% for most people. Track actual weight changes over 2-3 weeks to calibrate your true TDEE — that's more accurate than any formula.