BMI Calculator

Calculate your Body Mass Index

kg
cm

What is Body Mass Index (BMI)?

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared.

BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.

BMI Formula (Metric)

Weight (kg) ÷ [Height (m)]²

Example: 70kg ÷ (1.75m × 1.75m) = 22.9

BMI Formula (Imperial)

[Weight (lbs) ÷ Height (inches)²] × 703

Example: (154lbs ÷ 70in²) × 703 = 22.1

BMI Categories and Health Risks

BMI Range Category Health Risk
Below 18.5 Underweight Risk of nutritional deficiencies and osteoporosis
18.5 - 24.9 Normal weight Lowest risk of health problems
25.0 - 29.9 Overweight Moderate risk of developing health problems
30.0 and above Obese High risk of developing health problems

Important: BMI is a screening tool, not a diagnostic measure. Consult a healthcare provider for a comprehensive health assessment.

Limitations of BMI

What BMI Doesn't Consider

  • Muscle mass vs. fat distribution
  • Bone density
  • Ethnic and racial differences
  • Age and sex variations
  • Overall body composition

Who Should Be Cautious

  • Athletes with high muscle mass
  • Pregnant or breastfeeding women
  • Children and teenagers
  • Elderly individuals
  • People with certain medical conditions

Maintaining a Healthy Weight

Nutrition Tips

  • Eat a balanced diet with plenty of fruits and vegetables
  • Stay hydrated and limit sugary drinks
  • Practice portion control and mindful eating

Activity Recommendations

  • Aim for at least 150 minutes of moderate exercise weekly
  • Include strength training exercises twice a week
  • Incorporate more movement into your daily routine

Frequently Asked Questions

Is BMI accurate for athletes?

BMI may not be accurate for athletes or individuals with high muscle mass, as muscle weighs more than fat. These individuals might have a high BMI but low body fat percentage.

Should children use the same BMI categories?

No, children and teens need age and sex-specific BMI percentiles because their body composition varies as they grow.

How often should I check my BMI?

For most adults, checking BMI every few months is sufficient unless you're actively trying to change your weight. Focus more on overall health indicators rather than BMI alone.

Medical Disclaimer

This BMI calculator is for informational purposes only. It is not intended as medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of health conditions. Do not disregard professional medical advice because of something you have read on this website.