Home ▾ BMI Calculator

Free BMI Calculator

Calculate your Body Mass Index (BMI) quickly and accurately. This free BMI calculator shows your BMI value, weight category, and healthy weight range for your height.

BMI Calculator

0.0
Your BMI: Normal weight
Height-
Weight-
Healthy BMI Range18.5 - 24.9
Healthy Weight Range-

How to Use the BMI Calculator

Using this BMI calculator is simple. Choose between metric (centimeters and kilograms) or imperial (feet, inches, and pounds) units. Enter your height and weight, then click "Calculate" to get your BMI instantly.

The results show your BMI value (rounded to one decimal place), your weight category (underweight, normal, overweight, or obese), and your healthy weight range for your height. The World Health Organization (WHO) defines these BMI categories for adults:

  • Below 18.5 – Underweight
  • 18.5 - 24.9 – Normal weight
  • 25.0 - 29.9 – Overweight
  • 30.0 and above – Obese

Remember that BMI is a screening tool, not a diagnostic test. Athletes with high muscle mass may have a high BMI without having excess body fat.

BMI Formula

Metric formula:

BMI = weight (kg) / [height (m)]²

Imperial formula:

BMI = [weight (lbs) / height (in)²] × 703

Frequently Asked Questions

BMI is a useful screening tool for most adults, but it has limitations. It may overestimate body fat in athletes and underestimate it in older adults who have lost muscle mass. For a more complete picture, consider waist circumference and other health markers.
For adults (ages 18-65), the same BMI categories apply regardless of age. For children and teenagers, BMI is interpreted using age and sex-specific percentiles. For seniors, a slightly higher BMI (up to 27) may be considered healthy.
To lower your BMI, focus on a balanced diet with appropriate portion sizes and regular physical activity. Aim for at least 150 minutes of moderate exercise per week. Our Calorie Calculator can help you determine your daily calorie needs for weight management.

Related Tools