Health & Fitness

BMI Calculator

Check your Body Mass Index and see where you fall on the healthy range.

Your measurements

kg
cm

Your BMI

22.9

Normal weight
Under
Normal
Over
Obese
Healthy weight for your height
57 kg – 76 kg
BMI category
Normal weight

BMI is a screening tool, not a diagnosis. It doesn't distinguish muscle from fat or account for age, sex and body composition. For a full picture, speak with a healthcare professional.

About the BMI Calculator

Body Mass Index (BMI) is a quick screening number that relates your weight to your height. It's calculated as your weight in kilograms divided by the square of your height in metres, and it sorts adults into ranges: underweight (below 18.5), normal (18.5–24.9), overweight (25–29.9) and obese (30 and above).

BMI is popular because it's simple and a reasonable indicator of body-fat-related health risk across a population. But it's a blunt tool for individuals: it can't tell muscle from fat, so very muscular people may register as “overweight”, and it doesn't account for age, sex, ethnicity or where you carry weight. Use it as a starting point, not a verdict.

This calculator works in both metric and imperial units and shows the healthy weight range for your height, so you can see how far you are from the normal band.

Frequently asked questions

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². In imperial units it's weight (lb) ÷ height (in)² × 703. This calculator handles the conversion for you whichever units you enter.

What is a healthy BMI?

For most adults a BMI between 18.5 and 24.9 is considered the healthy range. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classed as obese.

Is BMI accurate for everyone?

No. BMI doesn't distinguish muscle from fat, so athletes can read as overweight, and it doesn't adjust for age, sex, ethnicity or fat distribution. It's a screening tool — for a fuller picture consider body-fat percentage and a chat with a clinician.

Does BMI work differently for children?

Yes. For children and teens, BMI is interpreted using age- and sex-specific percentiles rather than the fixed adult ranges. This calculator is intended for adults.

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