Health calculator

BMI calculator

Calculate adult body mass index, see the BMI category, and compare the reference weight range for your height.

Use BMI with care

BMI is an adult indicator. It is not a diagnosis and does not directly measure body fat.

Interpretation limits

BMI can be less representative for people with high muscle mass, older adults, pregnant people, children, and adolescents.

Calculate BMI

Choose unitsKilograms and centimetersPounds, feet and inches

Weight in kilograms

Example: 70

Height in centimeters

Example: 175

Result

Enter height and weight to calculate BMI.

Your values stay in this browser. They are not stored, logged, or added to the URL.

BMI formula

Metric BMI formula

BMI = weight in kilograms / height in meters²

Metric inputs use kilograms and centimeters, with centimeters converted to meters before calculation.

Imperial conversion

1 lb = 0.45359237 kg; 1 in = 0.0254 m

Imperial inputs are converted to kilograms and meters before the same BMI formula is applied.

Adult BMI categories

Underweight	Below 18.5	A lower adult BMI range.
Healthy weight	18.5 to 24.9	The adult BMI range often used as a reference.
Overweight	25.0 to 29.9	A higher adult BMI range.
Obesity class I	30.0 to 34.9	First adult obesity class.
Obesity class II	35.0 to 39.9	Second adult obesity class.
Obesity class III	40.0 or greater	Third adult obesity class.

Examples

70 kg and 175 cm

weight = 70 kg, height = 175 cm

BMI = 22.9, Healthy weight, reference range 56.7 to 76.3 kg

150 lb and 5 ft 9 in

weight = 150 lb, height = 5 ft 9 in

BMI = 22.2, Healthy weight, reference range 125.3 to 168.6 lb

FAQ

Is BMI a diagnosis?

No. BMI is an adult indicator and should be interpreted with other health information.

Who is this adult BMI calculator for?

It is intended for adults. Children and adolescents require age- and sex-specific interpretation.

Why can BMI be misleading?

BMI does not directly measure body composition, muscle mass, or fat distribution.