BMI Calculator
Calculate your Body Mass Index. Supports metric (kg/cm) and imperial (lb/in) units.
Your BMI
UnderweightNormalOverweightObese
<18.5253040+
BMI Categories (WHO)
| Category | BMI Range | Risk |
|---|---|---|
| Underweight | < 18.5 | Increased |
| Normal weight | 18.5 – 24.9 | Minimal |
| Overweight | 25 – 29.9 | Increased |
| Obese Class I | 30 – 34.9 | High |
| Obese Class II | 35 – 39.9 | Very High |
| Obese Class III | ≥ 40 | Extremely High |
⚠️ BMI is a screening tool, not a diagnostic measure. Consult a healthcare professional for medical advice.
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Frequently Asked Questions
Body Mass Index (BMI) is a value derived from a person's height and weight. It's calculated as weight (kg) divided by height squared (m²). It's used as a simple screening tool to categorize body weight.
BMI is a useful population-level screening tool, but has limitations. It does not account for muscle mass, bone density, age, or fat distribution. Athletes may have a high BMI despite low body fat. Always consult a doctor for a complete health assessment.
According to the WHO, a BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is classified as obese.
Metric: BMI = weight(kg) ÷ height(m)². Imperial: BMI = (weight(lb) ÷ height(in)²) × 703.