BMI Calculator

Work out your Body Mass Index (BMI) from your height and weight. Free, private, and instant.

Enter your height and weight to work out your Body Mass Index (BMI).

Height (cm)

Weight (kg)

Your BMI will appear here.

About This BMI Calculator

What is a BMI Calculator?

A BMI calculator works out your Body Mass Index (BMI), a number that shows whether your weight is in a healthy range for your height. BMI is worked out by dividing your weight in kilograms by your height in metres squared. It is a simple guide, not a medical diagnosis.

How to use it, step by step

Enter your height in centimetres (cm).
Enter your weight in kilograms (kg).
Click Calculate BMI.
Read your BMI and its category: Underweight, Normal, Overweight, or Obese.

BMI categories

Underweight is below 18.5. Normal is 18.5 to 24.9. Overweight is 25 to 29.9. Obese is 30 and above.

Who it helps

Anyone who wants a quick idea of whether their weight is in a healthy range. People starting a health or fitness plan. Anyone who wants a simple number to track over time.

Features and benefits

Free to use, with no sign-up and no limits.
Shows your BMI to one decimal place, with its category.
Works with height in cm and weight in kg.
Private: nothing is stored or sent anywhere.

Please note: BMI is a simple guide. It does not suit everyone, for example athletes with a lot of muscle. For health advice, talk to a doctor.

Frequently Asked Questions

What is a healthy BMI?

A BMI of 18.5 to 24.9 is the normal range.

Is BMI accurate for everyone?

BMI is a simple guide. It does not suit everyone. Athletes with a lot of muscle can have a high BMI while being healthy, and children need a different measure.

Is my height and weight saved?

No. They are only used in your browser to work out your BMI. Nothing is stored or sent anywhere.