What is BMI?
Body Mass Index (BMI) is a simple measurement that uses your height and weight to estimate body fat. It's used by doctors, nutritionists, and fitness professionals worldwide as a quick health screening tool.
The formula is simple: BMI = weight (kg) / height² (m²).
BMI Categories
After calculation, your BMI falls into one of these categories:
| Category | BMI Range |
|---|---|
| Underweight | Below 18.5 |
| Normal Weight | 18.5 - 24.9 |
| Overweight | 25 - 29.9 |
| Obese Class I | 30 - 34.9 |
| Obese Class II | 35 - 39.9 |
| Obese Class III | 40 and above |
How to Use Our BMI Calculator
- Choose Your Unit: Toggle between Metric (kg/cm) or Imperial (lbs/ft+in)
- Enter Your Details: Age, gender (optional but helps with body fat estimation), height, and weight
- Click Calculate: View your BMI score, category, and healthy weight range
Understanding Your Results
The calculator provides:
- BMI Score: Your numeric BMI value
- Health Category: Which category you fall into
- Healthy Weight Range: The ideal weight range for your height
- Body Fat Percentage (if age and gender are provided): Additional insight into your body composition
Important Notes
- BMI does not directly measure body fat — athletes with high muscle mass may have a high BMI but low body fat
- BMI should be used as a screening tool, not a diagnostic tool
- Always consult a healthcare provider for a complete health assessment
- BMI ranges may vary slightly for different ethnic groups
Tips for a Healthy BMI
- Maintain a balanced diet rich in fruits, vegetables, and whole grains
- Exercise regularly — aim for at least 150 minutes of moderate activity per week
- Get adequate sleep (7-9 hours for adults)
- Stay hydrated
- Monitor your weight regularly
Our BMI Calculator provides accurate BMI scores, body fat estimates, and healthy weight ranges for your height.