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Health & Fitness WHO Standards

BMI Calculator

Calculate your Body Mass Index (BMI), view official World Health Organization weight categories, and discover your recommended healthy weight range.

Your BMI Score Normal weight
22.9

Normal weight

Healthy Weight Range 56.7 – 76.3 kg
Measurement Standard World Health Organization (WHO)

WHO Adult BMI Classification

Official classification standards for adults aged 20 and older

Underweight < 18.5
Normal weight 18.5 – 24.9 Your Range
Overweight 25.0 – 29.9
Obesity Class I 30.0 – 34.9
Obesity Class II 35.0 – 39.9
Obesity Class III ≥ 40.0

Understanding Body Mass Index (BMI)

Body Mass Index (BMI) is a clinical screening metric that quantifies an individual's tissue mass (muscle, fat, and bone) relative to height. Formulated in the 19th century by Belgian polymath Adolphe Quetelet, it is universally adopted by the World Health Organization and medical authorities as a straightforward population health assessment tool.

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The Metric & Imperial BMI Formulas

Metric: BMI = Weight (kg) ÷ [Height (m)]^2 | Imperial: BMI = 703 × Weight (lbs) ÷ [Height (in)]^2

Where:

  • BMI = Body Mass Index in kg/m²
  • Weight = Body mass in kilograms or pounds
  • Height = Stature in meters or inches
  • 703 = Conversion factor for pounds and inches to metric units

Note: BMI does not directly measure body fat percentage or fat distribution (visceral vs subcutaneous fat).

Health Significance of BMI Ranges

Maintaining a healthy BMI between 18.5 and 24.9 is statistically associated with the lowest risk of cardiovascular disease, type 2 diabetes, hypertension, and all-cause mortality. Individuals in the overweight (25.0–29.9) or obesity (≥ 30.0) brackets face progressively higher risks of metabolic dysregulation.

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Frequently Asked Questions

Common questions and clear answers about this calculator

According to the World Health Organization (WHO), a BMI between 18.5 and 24.9 is considered normal or healthy weight for adult men and women.