Mathematical Formula
How Is BMI Calculated?
Understand the exact formula used by CDC and medical systems.
See how weight and height convert into your numerical index score.
Understand the exact formula used by CDC and medical systems.
See how weight and height convert into your numerical index score.
BMI = Weight (kg) ÷ [Height (m)]²
Example: A person weighing 70 kg who is 1.75 m tall:
1.75 × 1.75 = 3.0625
70 ÷ 3.0625 = 22.86 (Healthy range)
Created by Belgian mathematician Adolphe Quetelet in the 1830s.
BMI = [Weight (lbs) × 703] ÷ [Height (inches)]²
Why 703? It converts pounds to kilograms and inches to meters in a single step.
5 feet 10 inches = 70 inches total.
Calculate your BMI in seconds with automatic Imperial & Metric unit conversions.
Educational tool only. Does not replace individualized clinical diagnosis.