Clinical tools

Each calculator shows the formula it used and where that formula comes from — learn the derivation, not the output.

BMI & body surface area

Weight category and the BSA used for drug and fluid dosing.

Weight (kg)60

Height (cm)165

BMI22 kg/m²WHO: Normal

Asia-Pacific categoryNormalLower cut-offs apply to South Asian populations

Body surface area1.66 m²Mosteller

Formula

BMI = weight / height² · BSA (Mosteller) = √(height[cm] × weight[kg] / 3600)

Source: WHO BMI classification (Asian cut-offs shown separately); Mosteller RD, NEJM 1987