BMI Calculator

Get your BMI and the WHO weight category from your height and weight — the same number your doctor's chart uses.

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What it does

The BMI Calculator applies the standard weight-divided-by-height-squared formula and drops the result into the WHO band — underweight, normal, overweight, or one of the obese categories — the same chart your GP has on the wall. It accepts either metric (cm, kg) or imperial (feet/inches, lbs), so you don't have to convert your height first.

How to use it

  1. Select your preferred unit system: metric (cm/kg) or imperial (inches/lbs).
  2. Enter your height in the appropriate unit.
  3. Enter your weight in the appropriate unit.
  4. View your BMI score and weight category instantly.
  5. The color-coded result indicates your category: underweight, normal, overweight, or obese.

Key features

Why it helps

Fine as a screening number and a way to track your own trend over time; not a diagnosis. BMI treats muscle and fat the same, so it overstates the risk for athletic builds and understates it for people who carry weight around the waist. Use the number as one signal alongside waist measurement, blood work and how you actually feel — not as the whole picture.

Frequently asked questions

What is BMI?

BMI uses height and weight to estimate if your weight is healthy. Calculated as weight / height².

What are the BMI categories?

Underweight: <18.5, Normal: 18.5-24.9, Overweight: 25-29.9, Obese: 30+.

Is BMI accurate for everyone?

It's a screening tool but doesn't account for muscle mass or body composition.

Can I use both metric and imperial units?

Yes, supports both systems.

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