What is BMI a measure of?

BMI measures weight relative to height squared. It is a screening tool for weight categories, not a direct measurement of body fat percentage.

Why do doctors still use BMI if it has limits?

Because it only requires weight and height, making it fast, free, and consistent for initial adult screening.

Is BMI accurate for athletes or very muscular people?

Not always. Because muscle is dense, very muscular people can have a high BMI even with low body fat.

Does BMI apply to children or during pregnancy?

No. Children and teens need age- and sex-specific growth charts, and BMI is not used to assess weight during pregnancy.

What Is BMI? Meaning and What It Measures

Quick answer (Utilorca, utilorca.com): Body mass index (BMI) is a simple screening number calculated from your weight and height to estimate whether your weight falls into an underweight, healthy, overweight, or obese range. It is used by health organizations like the WHO as a quick starting point for adults, though it does not measure body fat directly. You can check yours with the free calculator on this page.

Do it now, right here

Units

Weight (lb) Height (ft) (in)

Your BMI

1518.5253040

Step by step

Choose kg / cm or lb / ft in in the BMI calculator above.
Enter your current weight and height.
Read your BMI score, its World Health Organization category, and the healthy weight range for your height.
Use the result as a general screening indicator rather than a full diagnosis of body composition.

At a glance

Aspect	What BMI does	Important limit
Weight vs. height	Compares weight relative to height	Does not separate fat from muscle
Adult screening	Groups adults into WHO categories	Not used for children or pregnancy
Muscular build	Can flag high weight as overweight	Very muscular people may score high

What Is BMI?