Is BMI a good measure of health?

It is a screening tool for populations, not a diagnosis for a person. It uses only height and weight, so it cannot tell muscle from fat and misclassifies athletes and the elderly in opposite directions. Waist measurement adds most of what it misses, which is why this page asks for it.

Why do the healthy ranges differ for South Asians?

Because cardiometabolic risk appears at a lower BMI in South, South-East and East Asian populations. The WHO published lower action points for these groups, so the same figure of 24 falls in different bands depending on which standard is selected here.

Health & Fitnessbody composition

BMI Calculator

BMI with the region's own thresholds applied. India uses lower overweight and obesity cut-offs than the standard WHO values, and almost no competitor applies them.

Also called: body mass index calculator, am i overweight.

BMI

23.7

A BMI of 23.7, which falls in the healthy band on the WHO thresholds. Your healthy weight range for this height is 58.6–79.2 kg.

Band

healthy

Thresholds applied

WHO

Healthy range from (kg)

58.6

Healthy range to (kg)

79.2

Same figure from lb and in

23.7

Distance to the healthy range (kg)

Waist to height ratio

What the waist says

Add a waist measurement to check what BMI cannot see: it counts mass without knowing where it sits.

How this is calculated

Method and background

This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.

How this is calculated

Mass divided by height squared. The familiar 703 in the imperial form is not a magic number. It is the pure unit conversion 0.45359237 ÷ 0.0254², which comes to 703.07. BMI does not distinguish fat from muscle and was developed on European populations; Asian populations carry elevated metabolic risk at lower BMI, which is why the India thresholds sit at 23 and 25 rather than 25 and 30.

bmi = kg / m^2, or 703 * lb / in^2

kg: Mass in kilograms (kg)
m: Height in metres (m)

Full derivation: BMI, and where the 703 comes from

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

75 kg at 178 cm

Weight (kg): 75
Height (cm): 178
Apply the thresholds for: The standard WHO bands

BMI23.7

75 / 1.78^2, independently computed

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India thresholds classify the same figure differently

Weight (kg): 75
Height (cm): 178
Apply the thresholds for: My region: India uses lower cut-offs

BMI23.7

India's overweight cut-off is 23, not 25 (DRV-013)

Open this example

the imperial form agrees, which is what the 703 is for

Weight (kg): 75
Height (cm): 178
Apply the thresholds for: The standard WHO bands

BMI23.7

DRV-013: 703 is exactly 0.45359237 / 0.0254^2

Open this example

Method and limits

What it assumes

BMI is a population screening measure, not a diagnosis or a measure of body composition.

What it deliberately does not model

Does not distinguish fat from muscle. A trained athlete can register as overweight on BMI alone.
Not valid for children, for whom percentile charts are used instead, or during pregnancy.

Sources

WHO: Body mass index (standards body)

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Is BMI a good measure of health?: It is a screening tool for populations, not a diagnosis for a person. It uses only height and weight, so it cannot tell muscle from fat and misclassifies athletes and the elderly in opposite directions. Waist measurement adds most of what it misses, which is why this page asks for it.
Why do the healthy ranges differ for South Asians?: Because cardiometabolic risk appears at a lower BMI in South, South-East and East Asian populations. The WHO published lower action points for these groups, so the same figure of 24 falls in different bands depending on which standard is selected here.