BMI Calculator
Body Mass Index using metric or imperial units, with WHO categories.
How to Use This Calculator
Choose between metric (centimeters and kilograms) or imperial (feet, inches, and pounds) units using the tabs above. Enter your height and weight, and your BMI calculates instantly along with the corresponding World Health Organization (WHO) weight category: Underweight, Normal weight, Overweight, or Obese.
Body Mass Index is a screening tool that estimates body fat based on height and weight. While it's widely used by health professionals, it doesn't directly measure body fat and may not accurately reflect health for athletes, older adults, or those with higher muscle mass.
Understanding BMI Categories
- Underweight (BMI < 18.5): May indicate malnutrition, eating disorders, or other health issues
- Normal weight (BMI 18.5–24.9): Associated with lower risk of weight-related health conditions
- Overweight (BMI 25–29.9): May increase risk of heart disease, diabetes, and other conditions
- Obese (BMI ≥ 30): Significantly higher risk of serious health problems including heart disease, stroke, and type 2 diabetes
Tips & Limitations
BMI doesn't measure body composition: Two people with the same BMI can have very different body fat percentages. Athletes with high muscle mass may have an "overweight" BMI despite being very healthy.
Age and gender matter: Older adults naturally have more body fat than younger adults at the same BMI. Women typically have more body fat than men at the same BMI.
Use BMI as one indicator: Combine BMI with waist circumference, body fat percentage, blood pressure, cholesterol levels, and family history for a complete health picture. Always consult a healthcare professional for personalized advice.