BMI calculator On-device
Body mass index with healthy-weight range
BMI is a rough screening measure, not a diagnosis — talk to a clinician for personal advice.
Free BMI calculator with metric and imperial units, WHO categories and your healthy-weight range. Works entirely on your device.
About this tool
What you provide
- Your height and weight, in cm and kg or in ft-in and lb
- Your age, optional
What you get
- Your BMI and the WHO category it falls in
- The healthy weight range for your height
Limits
- BMI is a rough screening measure, not a diagnosis — talk to a clinician for personal advice.
- Adult BMI categories do not apply to children and teens; entering an age under 18 shows that note instead of a category.
- Runs entirely on your device and your numbers are never uploaded.
How to use it
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Choose your units
Press cm / kg or ft-in / lb; the height and weight fields switch to the units you picked.
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Enter height and weight
Type your height and weight, and your age in the optional age field if you want the tool to check whether the adult categories apply to you.
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Read your BMI
The number and its WHO category appear with a marker on a 15–40 scale and the healthy weight range for your height; entering an age under 18 replaces all of that with the growth-chart note.
Frequently asked questions
How do I calculate my BMI?
Enter your height and weight and the tool instantly computes your body mass index along with a healthy-weight range for comparison. Everything runs on your device, so your numbers are never uploaded.
Is this BMI calculator free to use?
Yes, it's completely free and requires no signup.
Does my BMI tell me if I'm healthy?
No, BMI is a screening number only, not a diagnosis. For a full health assessment, consult a clinician.