BMI, and what an underwriter does with it

Body mass index is one of the standard inputs to a life insurance application. Here is the number, the bands it sits in, and an honest account of what it does and does not decide.

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BMI is weight in kilograms divided by height in metres squared. The bands are set out below.

This is an estimate based on the figures you entered. It is not a quotation, and it does not reflect any insurer's product terms or pricing. What a policy actually costs is set by the insurer at underwriting.

Nothing you type here leaves your browser. There is no server involved, no record kept, and nothing sent anywhere — you can close the tab and it is gone.

How this is worked out

Weight in kilograms divided by height in metres, squared.

BMI = weight (kg) ÷ height (m)²

The bands below are the World Health Organization's general classification.

Band	BMI
Underweight	Below 18.5
Normal range	18.5 to 24.9
Overweight	25.0 to 29.9
Obese	30.0 and above

Insurers do not all use these bands. Each sets its own acceptable range, and some apply different thresholds for South Asian populations. What the bands are useful for here is understanding roughly where a figure sits — not predicting a decision.

A figure outside an insurer's standard range does not end an application. It routes it to a human underwriter, who assesses the whole case rather than one number.

Questions people ask

Why does a life insurer ask for height and weight at all?

Build is one of the standard inputs to assessing mortality risk, alongside age, health history and tobacco use. It is asked on almost every proposal form, and a figure well outside the usual range is one of the things that sends an application to a person rather than through a template.

Does a high BMI mean I will be refused?

No. It means an underwriter looks at the case individually rather than pricing it off a standard table. Most applications are accepted; some are accepted on altered terms. What this site cannot tell you is which — that is the insurer's decision, made after seeing the whole application.

Is BMI a good measure of health?

It is a crude one, and widely criticised as such. It takes no account of muscle, frame or body composition, so a very muscular person can register as overweight. Insurers use it because it is cheap, standardised and comparable — not because it is precise.

Should I lose weight before applying?

That is a question for a doctor, not a website, and this site does not give health advice. What is worth knowing is that a recent weight change of more than about ten kilograms is itself something proposal forms ask about, in either direction.