BMI Standards & Authority Guide

Anthropometric Analysis: The Quetelet Index & BMI

Body Mass Index (BMI) is a heuristic proxy for human body fatness based on an individual's mass and height. Originally developed by the Belgian polymath Adolphe Quetelet in 1832, it remains the primary screening tool for obesity and malnutrition in global clinical populations due to its accessibility and low cost.

Standard WHO Classification Matrix

Precision Formula: Metric vs. Imperial

While this tool automates the process, the underlying mathematical framework depends on the square of the height to account for the increasing volume of a body as it scales vertically.

BMI = weight (kg) / height² (m)

BMI = 703 × weight (lb) / height² (in)

The "New BMI" (Oxford Formula)

Introduced by Nick Trefethen of Oxford University, the "New BMI" argues that the traditional formula is biased. Shorter people were told they were thinner than they were, and tall people were told they were fatter. This updated model uses a power of 2.5 to better reflect human volume:New BMI = 1.3 × weight (kg) / height²·¹ (m)