Free Online BMI Calculator

1. Pick metric (kg / cm) or imperial (lbs / ft + in) at the top.
2. Enter your weight and height in the labelled inputs.
3. Your BMI value and WHO category appear immediately below.
4. Read the highlighted band relative to the four ranges shown on the page.

BMI = weight (kg) ÷ height (m)². For imperial input the equivalent formula is weight (lb) × 703 ÷ height (in)². The WHO bands are: underweight <18.5, normal 18.5–24.9, overweight 25–29.9, and obese ≥30.

BMI is a screening tool, not a diagnosis. It correlates with body-fat percentage well enough for population-level studies but misreads individuals at the edges — athletes with high muscle mass tend to score "overweight", and older adults can score "normal" while carrying excess visceral fat. Clinicians pair it with waist circumference, blood pressure, and lab work.

This page accepts kg/cm or lbs/ft+in, prints BMI to one decimal place, and highlights the WHO band. General information only — verify any health-related decision with a clinician.