Health & Fitness

BMI Calculator

Calculate your Body Mass Index (BMI) and determine your weight category based on WHO standards.

Calculator Inputs

kg
cm

Ready to Calculate

Enter your weight and height to calculate your BMI.

What is BMI Calculator?

Body Mass Index (BMI) is a widely used screening tool that estimates body fat based on your weight and height. Healthcare professionals use BMI to identify potential weight-related health risks and categorize individuals into different weight classes. While BMI doesn't directly measure body fat percentage or distribution, it provides a quick, non-invasive method to assess whether someone may be underweight, normal weight, overweight, or obese. This calculator uses the standard BMI formula: weight (kg) / height² (m²), which has been validated across numerous population studies worldwide.

How to Use This Calculator

  1. 1Enter your current weight in either kilograms or pounds
  2. 2Input your height using feet and inches, or centimeters
  3. 3Select your preferred unit system (metric or imperial)
  4. 4Click Calculate to see your BMI score and weight category
  5. 5Review the detailed results including health recommendations

Understanding Your Results

Your BMI result falls into one of four categories defined by the World Health Organization: Underweight (below 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), or Obese (30 and above). Each category carries different health implications. A BMI below 18.5 may indicate malnutrition or other health concerns, while a BMI above 25 increases risks for cardiovascular disease, type 2 diabetes, and certain cancers. However, BMI has limitations - it doesn't account for muscle mass, bone density, overall body composition, or age and sex differences. Athletes with high muscle mass may have elevated BMIs despite being healthy, while older adults might have normal BMIs but reduced muscle mass.

Example:

For example, a person weighing 70 kg (154 lbs) with a height of 1.75 m (5'9") would have a BMI of 22.9, placing them in the normal weight category. If the same person gained 15 kg, their BMI would increase to 27.8, moving them into the overweight category. Conversely, someone who is 1.85 m (6'1") tall and weighs 90 kg (198 lbs) would have a BMI of 26.3, also in the overweight range, despite having different absolute measurements.

Important Tips & Considerations

  • BMI is most accurate for average adults aged 18-65
  • Not suitable for pregnant women, athletes, or bodybuilders
  • Consider waist circumference and body fat percentage for complete assessment
  • Consult healthcare providers before making major lifestyle changes
  • Track BMI changes over time rather than focusing on single measurements

Frequently Asked Questions