BMI Calculator.
Calculate Body Mass Index from weight and height. Get category instantly.
Calculations happen in your browser
Local processing
Conversions happen in your browser. Nothing is uploaded.
Instant results
Native browser APIs mean no server queue, no waiting room.
No account needed
Open, drop, convert. No sign-up, no email, no friction.
Frequently asked questions
Is BMI a reliable health measure?
BMI is a rough proxy based on the population, not on you specifically. It doesn't distinguish muscle from fat.
What categories are used?
WHO standard: under 18.5 underweight, 18.5-24.9 normal, 25-29.9 overweight, 30+ obese.
Does this work for children?
No. Children use age- and sex-specific percentile charts, not adult BMI ranges.
Are my files really not uploaded?
Correct. Every conversion in this tool runs in your browser using JavaScript and the local file APIs. There is no server-side processing, no file upload, no temporary storage, and no log of what you converted. You can verify this by opening your browser's network tab while converting — the only traffic is loading the page itself.
Do I need an account or to install anything?
No. Open the page, drop your file, download the result. No signup, no email, no extension, no app.
Is there a file-size limit?
Not from us. The practical limit is your device's memory — browser tabs typically handle files in the hundreds of megabytes range without issues. Very large files may take longer to process on phones than on laptops.