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BMI Calculator

Calculate body mass index from height and weight in metric or imperial units.

How to use BMI Calculator

  1. Choose Metric (centimetres and kilograms) or Imperial (inches and pounds).
  2. Enter your height and weight. The BMI figure and category update as you type.
  3. Read the healthy weight range for your height and the disclaimer at the bottom.

About BMI Calculator

Body Mass Index (BMI) is a simple screening number derived from height and weight. It divides the population into broad bands: underweight, normal, overweight and obese. It is not a diagnostic tool.

BMI does not distinguish between muscle and fat, does not consider waist circumference or distribution of fat, and is not appropriate for children, pregnant people, athletes and some other groups. Always talk to a qualified health professional about weight and health.

Features

  • Metric (cm/kg) and Imperial (in/lb) units
  • Instant BMI, category and healthy weight range
  • Visual scale showing where your BMI sits
  • Clear disclaimer that this is not medical advice

Frequently asked questions

Is BMI accurate for everyone?

No. It can misclassify muscular adults, athletes, older adults and some ethnic groups. It is a population-level screening tool, not a personal diagnosis.

What is a healthy BMI?

For most adults the World Health Organization regards 18.5–24.9 as the normal range. Lower is underweight, 25–29.9 is overweight, and 30 or higher is obese.

Should I act on the result?

Use the figure as a rough guide only. If you have concerns about your weight or health, speak to a doctor or dietitian.

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