What is a healthy BMI?

For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight range according to WHO guidelines.

Is BMI accurate for everyone?

BMI does not distinguish between muscle and fat, so it can overestimate body fat in muscular people and underestimate it in older adults with reduced muscle mass.

Does BMI differ for men and women?

The BMI formula itself is the same for everyone; it does not adjust for sex, though body composition norms can differ between men and women.

Health & Fitness

BMI Calculator

Enter your height and weight to calculate your Body Mass Index, see which category it falls into, and find a healthy weight range for your height.

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Enter your height and weight above to calculate your BMI.

This result is an estimate for informational and educational purposes. It isn’t a diagnosis and isn’t a substitute for advice from a doctor, registered dietitian, or other qualified professional. See our methodology and sources for the formula used and its limitations.

How it works

BMI is calculated by dividing your weight in kilograms by the square of your height in metres. The result is compared against standard World Health Organization thresholds to place it into an underweight, normal weight, overweight, or obesity category.

Formula & methodology

BMI = weight (kg) ÷ height (m)². Categories: under 18.5 is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 or above is obesity.

Worked example

A person who is 175 cm tall and weighs 70 kg has a BMI of 22.9, which falls in the normal weight range.

Important notes

—BMI is a screening tool, not a diagnosis — it does not directly measure body fat and can be less accurate for athletes, older adults, or during pregnancy.
—Use the Body Fat Calculator and Ideal Weight Calculator alongside BMI for a fuller picture.