BMI Calculator

A weight of 70 kg at a height of 1.75 m gives a BMI of 22.9 — the WHO "Normal weight" screening band.

How it works

• Converted the weight to kilograms and the height to metres.
• Divided the weight by the square of the height.
• Placed the value in the WHO adult screening band.

BMI = weight (kg) / height (m)² = 70 / (1.75)² = 22.9

• BMI is a screening index, not a diagnosis or a measure of body fat.
• The WHO bands do not apply unchanged to children, athletes, pregnant people or older adults.
• This is not medical advice; speak to a clinician about your own health.

Methodology

1. Convert the weight to kilograms (1 lb = 0.45359237 kg) and the height to metres (1 in = 2.54 cm).
2. BMI = weight in kg ÷ (height in metres)².
3. Classify with the WHO adult bands: below 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30 and above obesity.
4. The healthy-weight range is the mass at BMI 18.5 to 24.9 for the same height.

Usage

1. Enter your weight and choose kilograms or pounds.
2. Enter your height and choose centimetres or inches.
3. Read the BMI, the WHO screening band and the healthy-weight range for that height.

Examples

These are examples, not current values: they use fixed inputs, while the interactive tool computes live results in your browser.

Metric 70 kg, 175 cm

{
  "weight": 70,
  "weightUnit": "kg",
  "height": 175,
  "heightUnit": "cm"
}

Imperial 154 lb, 69 in

{
  "weight": 154,
  "weightUnit": "lb",
  "height": 69,
  "heightUnit": "in"
}

Metric 95 kg, 180 cm

{
  "weight": 95,
  "weightUnit": "kg",
  "height": 180,
  "heightUnit": "cm"
}

Limitations

What BMI is

Body mass index is a simple ratio of weight to the square of height, used by the World Health Organization as a population-level screening tool. It is fast and cheap, which is why it is widely used, but it is deliberately coarse: it does not measure body fat, fitness or health directly. Treat it as one signal among many, never as a verdict.

Disclaimer

This calculator is a screening estimate for information only and is not medical advice. It cannot diagnose any condition and it does not replace an assessment by a qualified healthcare professional. If you have health concerns, consult a clinician rather than relying on this number.