BMI calculator
Height and weight to BMI and a WHO adult label. Not medical advice.
Runs in this tab. The file stays here.
This runs in your browser. Nothing is uploaded.
About BMI calculator
Computes body mass index from height in centimetres and weight in kilograms, with WHO adult categories. Not medical advice.
BMI is kg divided by metres squared. Clinics still use it as a blunt screening number. This page does that division, rounds to one decimal, and sticks the WHO adult label next to it: underweight, normal range, overweight, or obese. That's the entire feature.
Height in centimetres, weight in kilograms. No stone/lb toggle, convert first if you need to. The bands are adult cutoffs; kids need age charts I'm not shipping. Muscle, pregnancy, and a dozen other realities make the label less useful than the formula looks. I still print the number. I don't pretend it's a diagnosis.
No history graph, no body-fat guess, no sex or age question. Those belong in apps that claim more than a ratio. If you came here for medical advice, talk to a clinician who has your actual history, not a tab doing arithmetic.
I shipped the metric inputs on purpose. Dual-unit forms are where people type 5'10" into a centimetre box and then blame the calculator. Convert once on the unit page, then come back.
How to use BMI calculator
- 1Enter height in centimetres and weight in kilograms.
- 2Read the BMI and category label.
- 3Treat it as screening math, not a diagnosis.
What it won't do
- Adult WHO categories only, not paediatric charts.
- Metric inputs on this page.
Common questions
Which BMI categories do you use?
WHO adult cutoffs: under 18.5 underweight, 18.5–24.9 normal range, 25–29.9 overweight, 30+ obese. Plenty of people (athletes, older adults) need a different reading of the same number.
Is this medical advice?
No. It is a formula plus published labels. Health decisions need a human who knows more than two numbers.
Can I enter height in feet and inches?
Not here. Convert to centimetres on the unit converter, then paste that in. One unit system means fewer silent mix-ups.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation