BMI Calculator
Your BMI
Understanding Body Mass Index (BMI)
Body Mass Index (BMI) is a screening tool that estimates body fat by measuring the ratio of your height to your weight. It's calculated by dividing weight in kilograms by height in meters squared (kg/m²). While BMI can be a useful starting point, it has significant limitations and should never be used alone to assess health. Many factors affect your overall health beyond body weight: genetics, physical activity level, diet quality, sleep, stress, mental health, smoking, alcohol consumption, and family medical history. Healthcare providers use BMI as just one of many tools.
BMI Categories:
- Underweight: BMI less than 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obesity Class I: BMI 30 to 34.9
- Obesity Class II: BMI 35 to 39.9
- Obesity Class III: BMI 40 or higher
Important Limitations of BMI:
- Doesn't distinguish muscle from fat: A muscular person may have a high BMI but very low body fat, and vice versa
- Doesn't account for fat distribution: Abdominal fat carries higher health risks than fat stored elsewhere, but BMI doesn't measure this
- Same formula for everyone: Body composition differs by sex, age, and ethnicity, but BMI uses the same chart for all adults
- Not suitable for certain groups: Athletes, bodybuilders, pregnant women, people over 65, children/teenagers, or those with muscle-wasting conditions
🔒 Privacy-Friendly: All calculations happen in your browser. No personal health data is sent to any server.
⚠️ Medical Disclaimer: This calculator is for informational purposes only and is not a medical diagnosis. BMI is a screening tool, not a diagnostic tool. It cannot determine your actual body fat percentage or your health status. Always consult with a qualified healthcare provider for personal health advice and before making any decisions about your weight or health.