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BMI Calculator

Calculate your Body Mass Index (BMI) and understand your weight status

Calculate your Body Mass Index (BMI) to understand your weight status and potential health risks. BMI is a widely used screening tool that estimates body fat based on height and weight.

Calculator Inputs

Choose your preferred unit system

Enter height in centimeters or inches

Enter weight in kilograms or pounds

Results

Enter values above to see your results

How It Works

Enter your height and weight using metric or imperial units. The calculator determines your BMI and provides your weight category with health recommendations.

Worked Examples

Person 1.75m tall weighing 75kg

Height (m):175cm / 100= 1.75m
Height Squared:1.75 × 1.75= 3.0625
BMI Formula:75 / 3.0625= 24.49
Classification:Range 18.5-24.9= Normal Weight

Person 5'10" weighing 180 lbs

Imperial Formula:703 × (lbs / in²)= Setup
Height (in):(5 × 12) + 10= 70 inches
Calculation:703 × (180 / 70²)= 25.8
Classification:Range 25-29.9= Overweight

Tips & Best Practices

  • BMI is a screening tool, not a diagnostic test for body fat or health
  • Athletes and very muscular people may have high BMI without excess fat
  • BMI doesn't account for muscle mass, bone density, or fat distribution
  • Consult healthcare professionals for comprehensive health assessments
  • Focus on overall health habits rather than just the BMI number

Frequently Asked Questions

What is a normal BMI range?

A normal BMI range is 18.5 to 24.9. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is considered obese.

Is BMI accurate for everyone?

BMI has limitations. It doesn't distinguish between muscle and fat, so athletes may have high BMIs despite being healthy. Age, gender, and ethnicity can also affect interpretation.

What should I do if my BMI is too high or low?

Consult with a healthcare provider for personalized advice. Focus on healthy eating, regular exercise, and lifestyle changes rather than just the BMI number.

How often should I check my BMI?

BMI changes slowly with weight changes. Checking monthly or quarterly is usually sufficient unless you're actively trying to change your weight.