Is BMI a medical diagnosis?

No. BMI is a general screening measure only. This tool does not provide medical advice or diagnosis, consult a healthcare professional for personal health guidance.

BMI Calculator

Calculate Body Mass Index from height and weight.

Sex

Age

Height (cm)

Weight (kg)

BMI22.9

CategoryNormal weight

Estimated body fat18.1%

BMI chart

WHO adult cut-offs — the same for men and women

UnderweightBelow 18.5

Normal weight18.5 – 24.9

Overweight25 – 29.9

Obesity30 and above

Your range: Normal weight

Body fat chart — men

American Council on Exercise ranges

Essential fatBelow 6%

Athletes6 – 13.9%

Fitness14 – 17.9%

Average18 – 24.9%

Obese25% and above

Your range: Average

BMI itself uses one formula and one set of cut-offs for everyone, so your BMI number does not change with sex — what differs is body composition, which is why the body fat ranges above are shown per sex. BMI is a general screening measure only and does not diagnose body fatness or health. This is not medical advice, consult a healthcare professional for personal guidance.

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How to Use

1Enter your height and weight (metric or imperial).
2View your BMI value and category.

Features

Metric and imperial units
Standard WHO BMI categories
Not medical advice

Example

Input

175 cm, 70 kg

Output

BMI 22.9, Normal weight

Calculate Body Mass Index (BMI) from your height and weight and see which standard BMI category it falls into. This tool is for general informational purposes only and is not medical advice.

What BMI measures

Body Mass Index is your weight in kilograms divided by the square of your height in metres. Someone 175 cm tall weighing 70 kg has a BMI of 70 ÷ 1.75², which is about 22.9. It is quick, needs no equipment, and is used worldwide to screen adults for weight categories that are linked to health risks.

WHO adult categories

BMI	Category
Below 18.5	Underweight
18.5–24.9	Healthy weight
25.0–29.9	Overweight
30.0 and above	Obesity

These cut-offs are the same for adult men and women. Some health authorities, particularly in South and East Asia, use lower thresholds for Asian populations, for example treating 23 and above as overweight, because health risks rise at lower BMI levels in those groups.

Estimated body fat

If you enter your age and sex, the calculator also estimates body fat percentage using the Deurenberg formula, which predicts body fat from BMI, age and sex. It is shown against American Council on Exercise reference ranges, which, unlike BMI, differ for men and women. Treat it as a rough estimate; methods such as DEXA scans measure body fat directly.

Limitations of BMI

It cannot tell muscle from fat. Muscular athletes can be classed as overweight while being very lean.
It says nothing about where fat is carried. Waist measurement adds useful information.
It is not designed for children and teenagers, who are assessed with age- and sex-specific percentile charts.
It is less reliable in pregnancy, older age and some medical conditions.

BMI is a screening number, not a diagnosis. For advice about your own health, talk to a doctor or other qualified health professional.