What is a healthy BMI?

For most adults, a BMI between 18.5 and 25 is considered a healthy range. Below 18.5 is below the healthy range, 25 to 40 is above it, and above 40 is a higher-risk band.

Does BMI apply to everyone?

No. BMI is a general screening measure and does not apply well during pregnancy, to under-18s, or to very muscular people, since it cannot tell muscle from fat. Waist size and a full health assessment give a fuller picture.

Is this BMI checker a diagnosis?

No. It gives general information based on UK BMI and waist-size ranges. Always speak to a qualified clinician about your health.

Free Health Tool · Sutton Coldfield

What Does Your BMI Mean?

Body Mass Index compares your weight to your height. Add your waist size too for a fuller picture. Enter your numbers below — takes 15 seconds.

UK BMI ranges

Below healthy — under 18.5

Worth a check, especially if it's a recent change or you have other symptoms.

Healthy — 18.5 to 25

The range associated with the lowest general health risk for most adults.

Above healthy — 25 to 40

Common, and a good moment to get a fuller baseline with a health assessment.

Very high — above 40

Carries higher health risks — worth discussing with a clinician.

Waist size matters too

Where fat sits matters as well as how much — waist size adds useful context BMI alone can miss.

BMI has limits

It doesn't apply well during pregnancy, to under-18s, or to very muscular people, since it can't tell muscle from fat.

Want the full picture?

A health assessment measures BMI and waist size alongside blood pressure, cholesterol and blood glucose — with a GP consultation and a 12-month plan. From £99.

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