BMI Calculator
Calculate your Body Mass Index (BMI) instantly with health category interpretation.
📋 How to Use
- Select your unit system: Metric (kg/cm) or Imperial (lbs/ft).
- Enter your weight.
- Enter your height.
- Your BMI is calculated instantly.
- View your BMI category (Underweight, Normal, Overweight, or Obese) with a color-coded result.
Tip: For the most accurate BMI, measure your height without shoes and weigh yourself in the morning before eating.
About This Tool
BMI Calculator — Body Mass Index Calculator Online
BMI (Body Mass Index) is a widely used health screening tool that provides a simple measure of whether a person's weight is appropriate for their height. Our free online BMI calculator gives you an instant result along with a health category interpretation.
What Is BMI?
Body Mass Index is calculated by dividing weight (in kilograms) by the square of height (in meters):
BMI = weight (kg) / height (m)²
For Imperial units: BMI = (weight (lbs) × 703) / height (inches)²
BMI Categories (WHO Standard)
| BMI Range | Category | |-----------|----------| | Below 18.5 | Underweight | | 18.5 – 24.9 | Normal weight | | 25.0 – 29.9 | Overweight | | 30.0 – 34.9 | Obese Class I | | 35.0 – 39.9 | Obese Class II | | 40.0 and above | Obese Class III |
Limitations of BMI
BMI is a useful screening tool but has important limitations:
- Does not measure body fat directly: A muscular athlete may have a high BMI without excess fat.
- Does not account for fat distribution: Abdominal fat is more dangerous than fat in other areas.
- Age and gender differences: BMI norms vary by age and may differ between men and women.
- Ethnicity: Some research suggests different BMI cut-offs for different ethnic groups.
Healthy Weight Management Tips
- Combine BMI tracking with waist circumference measurement for better health assessment.
- Focus on healthy habits (balanced diet, regular exercise) rather than a number.
- Consult a healthcare provider for personalized weight management advice.
- Children's BMI is calculated differently using age and sex-specific growth charts.