Body Mass Index (BMI) Calculator
A clinical biophysical metric evaluating mass-to-stature proportionality calibrated against World Health Organization epidemiological standards.
How This Calculation Formula is Formulated
Developed in 1832 by Belgian polymath Adolphe Quetelet, the Body Mass Index evaluates human body mass scaled against the square of stature height: BMI = Weight (kg) ÷ [Height (m)]². Adopted by the WHO in 1995 (TRS 854), it provides a standard population-level proxy for assessing adiposity risks, alongside lower Asian cut-offs (The Lancet, 2004).
Variable Definitions & Measurement Units
Worked BMI Calculation (Metric & Imperial)
Consider an adult weighing 70 kilograms with a standing height of 175 centimeters (1.75 meters):
Why can two people with the same BMI look completely different?
BMI only uses weight and height, so it cannot distinguish muscle, fat, or bone density. A muscular athlete and a sedentary person can post an identical BMI with very different body-fat percentages - which is why CDC and WHO both call it a screening tool, not a diagnostic one.
It is least reliable for very muscular individuals, pregnant women, older adults, and children. Treat it as a conversation-starter with a doctor, not a final verdict.
Frequently Asked Questions About BMI Calculator
What's a healthy BMI for my height?
WHO defines 18.5–24.9 as healthy for most adults; 18.5–22.9 is often used for South/East Asian ancestry.
Why is BMI different for Indian people?
WHO's 2004 research found higher risk at the same BMI in Asian populations, so lower cut-offs are recommended.
Is BMI accurate for athletes?
Not reliably - it can't distinguish muscle from fat.
Can BMI be used for children?
No, age- and sex-specific percentile charts are needed.
Related Online Calculators
Frequently referenced alongside BMI Calculator.
Body Fat Percentage Calculator (BMI)
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Calorie Calculator
Calculate your daily calorie needs (TDEE) and BMR with the scientifically proven Mifflin-St Jeor equation. Get exact targets for weight loss, maintenance, or muscle gain.
BMI Calculator
Free Body Mass Index (BMI) calculator for men and women. Check your healthy weight range, WHO classifications, and ideal weight target with metric or imperial units.