BMI Calculator — Free Online Calculator
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Your BMI
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About This Calculator
Body Mass Index (BMI) is a simple measure of body fat based on height and weight. It is widely used as a screening tool to categorize individuals into weight status categories. While BMI does not directly measure body fat, it correlates with more direct measures of body fat and is a useful indicator of health risk.
Formula
Interpretation
| BMI Range | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| ≥ 30.0 | Obese |
References
Frequently Asked Questions
What is a healthy BMI range?
A healthy BMI range is 18.5 to 24.9 kg/m², according to the WHO. Values below 18.5 indicate underweight, 25–29.9 indicate overweight, and 30 or above indicate obesity.
Does BMI account for muscle mass?
No. BMI does not distinguish between muscle and fat. Muscular individuals (e.g., athletes) may have a high BMI but low body fat. BMI is a screening tool, not a diagnostic measure of body composition.
Is BMI accurate for children and adolescents?
For children aged 2–19, BMI is calculated the same way but interpreted using age- and sex-specific percentile charts (CDC growth charts). A child's BMI percentile, not the raw number, determines weight status.
What are the limitations of BMI?
BMI does not measure body fat directly, does not account for fat distribution, and may misclassify athletes or elderly individuals. Waist circumference and body composition analyses provide additional context.
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⚠ Medical Disclaimer
This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.