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BMI Calculator (kg, lb, cm, feet and inches)

Estimate body mass index from height and weight. Processing for supported tools happens locally in your browser.

This is a general estimate for information only, not medical advice or a diagnosis.

About BMI Calculator

Use this browser-based utility for everyday tasks. Review output before relying on it and retain a copy of important originals.

Read the BMI Calculator guide →

About BMI Calculator

A BMI calculator divides weight by height squared to give a screening estimate. Enter consistent metric values and use the result as general information rather than a diagnosis.

How to use BMI Calculator

  1. Enter your weight and choose kilograms or pounds.
  2. Enter your height and choose centimetres, inches, feet or feet and inches.
  3. Select Calculate BMI to see the estimate and the weight and height the tool used.
  4. Check that the numbers and units are right.
  5. Talk to a qualified professional about your health, because BMI is only a screening estimate.

What BMI cannot tell you

BMI does not separate muscle from fat, so a strong athlete can have a high BMI, and it does not show where fat is carried or how healthy your habits are. It is not used in the same way for children, who are judged on growth charts, or during pregnancy. Treat the number as a screening estimate and talk to a doctor or a dietitian about your own health.

Frequently asked questions

How do I calculate BMI with feet and inches?

Choose Feet and inches, enter the feet and the inches, then your weight in kg or pounds. The tool converts to centimetres and kilograms and shows the BMI. The formula is weight in kg divided by height in metres squared.

What is a normal BMI for adults?

The usual adult ranges are under 18.5 underweight, 18.5 to 24.9 normal weight, 25 to 29.9 overweight and 30 or more obesity. BMI is a screening estimate, not a diagnosis, so ask a doctor about your health.

Is BMI a medical diagnosis?

No. It is a screening estimate and cannot determine a person’s health on its own.

Why should I confirm the units?

Entering pounds as kilograms or centimeters as meters changes the result substantially. Use the labels shown by the calculator.

More Calculators tools

Want more detail, examples and answers to common questions? Read the BMI Calculator guide.

About BMI Calculator

A BMI calculator divides weight by height squared to give a screening estimate. Enter consistent metric values and use the result as general information rather than a diagnosis.

How to use BMI Calculator

  1. Enter your weight and choose kilograms or pounds.
  2. Enter your height and choose centimetres, inches, feet or feet and inches.
  3. Select Calculate BMI to see the estimate and the weight and height the tool used.
  4. Check that the numbers and units are right.
  5. Talk to a qualified professional about your health, because BMI is only a screening estimate.

What BMI cannot tell you

BMI does not separate muscle from fat, so a strong athlete can have a high BMI, and it does not show where fat is carried or how healthy your habits are. It is not used in the same way for children, who are judged on growth charts, or during pregnancy. Treat the number as a screening estimate and talk to a doctor or a dietitian about your own health.

Frequently asked questions

How do I calculate BMI with feet and inches?

Choose Feet and inches, enter the feet and the inches, then your weight in kg or pounds. The tool converts to centimetres and kilograms and shows the BMI. The formula is weight in kg divided by height in metres squared.

What is a normal BMI for adults?

The usual adult ranges are under 18.5 underweight, 18.5 to 24.9 normal weight, 25 to 29.9 overweight and 30 or more obesity. BMI is a screening estimate, not a diagnosis, so ask a doctor about your health.

Is BMI a medical diagnosis?

No. It is a screening estimate and cannot determine a person’s health on its own.

Why should I confirm the units?

Entering pounds as kilograms or centimeters as meters changes the result substantially. Use the labels shown by the calculator.

More Calculators tools

Want more detail, examples and answers to common questions? Read the BMI Calculator guide.