BMI Calculator
Body mass index from height and weight. Free, private and runs in your browser.
About BMI Calculator
BMI Calculator estimates your body mass index from your height in centimetres and weight in kilograms. BMI is a general screening number for adults and cannot show your overall health, so use it as a rough guide only.
How to use BMI Calculator
- Enter your height in centimetres and your weight in kilograms.
- Click “Calculate BMI”.
- Read your BMI and its adult category. Ask a doctor for personal health advice.
When is BMI Calculator useful?
- Get a quick reference number for adults
- Track a rough change over time
- Have a number to discuss with a health professional
Frequently asked questions
How is BMI calculated?
BMI equals weight in kilograms divided by height in metres squared.
Is this medical advice?
No. BMI is a simple estimate for adults and does not consider muscle, age or body type. Speak to a doctor for health advice.
Can I use it for children?
The categories shown are for adults. Children need age-specific growth charts.
Can I use it for children?
No. The categories are for adults aged 18 and over. For children, athletes or pregnancy, ask a doctor.
Is BMI Calculator free to use?
Yes. BMI Calculator is free, with no sign-up and no usage limits.
Is my data sent anywhere?
No. The work is done in your browser on your own device, so nothing you use here is sent to our servers.
Privacy and safety
BMI Calculator runs entirely in your browser. What you enter never leaves your device and nothing is kept after you close the page.