How to Use This Calculator
How to Calculate BMI
Enter your weight and height to instantly calculate your Body Mass Index and see your weight category.
Formula
BMI Formula
BMI = weight (kg) / height² (m²)
BMI Categories:
- Under 18.5: Underweight
- 18.5-24.9: Normal weight
- 25-29.9: Overweight
- 30+: Obese
Examples
Example
Person: 70kg, 170cm tall
BMI = 70 / (1.7 × 1.7) = 24.2 (Normal weight)
Frequently Asked Questions
Is BMI accurate for everyone?
BMI is a useful screening tool but doesn't distinguish between muscle and fat. Athletes with high muscle mass may have high BMI despite being healthy. It's less accurate for elderly people, pregnant women, and children.
What's a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. However, ideal BMI can vary by age, gender, ethnicity, and muscle mass.
How can I improve my BMI?
To lower BMI: eat a balanced diet, reduce calorie intake, and exercise regularly. To raise BMI: increase healthy calorie intake and strength training. Always consult a healthcare provider for personalized advice.