BMI Calculator
For adults aged 20 and over: calculate BMI and see its screening category from height and weight. BMI is not a diagnosis or an individual weight target.
About Body Mass Index
BMI is your weight in kilograms divided by the square of your height in metres. It is a quick screening tool for weight categories but does not directly measure body fat or account for muscle mass.
FAQ
What is a healthy BMI?
This page uses adult reference categories (20+). BMI 18.5–24.9 is the reference healthy-weight category, but an individual assessment needs more than BMI.
BMI is a general guide, not a diagnosis. Consult a health professional for advice.
Use the result with confidence
An adult screening number
This page uses adult BMI categories for people aged 20 and over. Enter height and weight in the selected unit system; do not put centimetres into the feet field. BMI is weight in kilograms divided by height in metres squared.
Follow the arithmetic
At 70 kg and 170 cm, first convert height to 1.70 m. BMI = 70 ÷ (1.70 × 1.70) = 24.22, displayed as 24.2. The adult reference boundaries on this page are 18.5, 25 and 30. A value near a boundary can cross it after a small measurement change.
What the number cannot tell you
BMI is a screening measure, not a diagnosis or a direct body-fat measurement. It does not distinguish muscle from fat. Children and teenagers need age- and sex-specific assessment; pregnancy and individual health circumstances need clinical interpretation. Do not use this result alone to set a weight target or treatment.