About BMI Calculator
Free informational BMI calculator computing standard Quetelet Body Mass Index, Nick Trefethen Oxford formula, BMI Prime, and Ponderal Index. Features healthy weight targets in kg and lbs with WHO classification ranges.
Key Capabilities & Features
- Standard Quetelet BMI calculation (weight / height²)
- Oxford formula computation (1.3 × weight / height^2.5) compensating for tall and short statures
- BMI Prime calculation showing ratio relative to upper normal boundary (25.0)
- Ponderal Corpulence Index (weight / height³) in kg/m³
- World Health Organization (WHO) color-coded category classification and healthy weight targets
How to Use BMI Calculator
Select Units
Toggle between Metric (kg, cm) and Imperial (lbs, ft-in) systems.
Enter Height & Weight
Input your stature and current body mass.
Inspect WHO Categories
Review your BMI score, Oxford adjustment, and optimal healthy target range.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Your data never leaves your browser.
Frequently Asked Questions
What is the Oxford BMI formula?
Created by mathematician Nick Trefethen at Oxford University, it scales height by the power of 2.5 (1.3 × weight / height^2.5) to better account for volumetric scaling in tall and short adults.
Is BMI diagnostic of body fat?
No. BMI is a population-level epidemiological screening tool. It does not differentiate between dense skeletal muscle and adipose tissue.