BMI Calculator

Body mass index and WHO category from height and weight.

Height (cm)

Weight (kg)

WHO categories (kg/m²)

< 18.5 — Underweight
18.5–24.9 — Normal
25–29.9 — Overweight
30–34.9 — Obese I
35–39.9 — Obese II
≥ 40 — Obese III

Body Mass Index

24.5

kg/m²

Body Mass Index (BMI)

BMI is weight divided by height squared (kg/m²) and gives a quick, standardised estimate of weight status. It is widely used as one input to surgical candidacy and peri-operative risk.

WHO categories

Underweight < 18.5, normal 18.5–24.9, overweight 25–29.9, and obesity class I (30–34.9), II (35–39.9) and III (≥ 40).

BMI in plastic surgery

Many procedures (e.g. body contouring, abdominoplasty) use BMI thresholds for safety and outcome; BMI is one factor alongside comorbidity, distribution of fat and patient goals.

Education only — BMI does not distinguish muscle from fat; follow local protocol and clinical judgement.