DocomintBMI Calculator
Calculate Body Mass Index from weight and height, with the standard weight category.
BMI (Body Mass Index) divides weight by height squared to give a single screening number the WHO and most health guidelines still use as a first-pass check — it's fast to compute but doesn't distinguish muscle from fat, so an athletic person can register as "overweight" despite low body fat, which Body Fat Calculator addresses more directly.
Example: A 70kg person at 175cm has a BMI of 22.9 (70 ÷ 1.75²) — squarely in the "Normal weight" 18.5–24.9 range used by most standard BMI charts.
How it works
- Enter your weight in kilograms and height in centimeters
- Press Calculate BMI
- Your BMI and weight category appear instantly, computed on your device
Frequently asked questions
What do the BMI categories mean?
Under 18.5 is classified Underweight, 18.5–24.9 Normal weight, 25–29.9 Overweight, and 30+ Obese — the WHO's standard adult categories, used as a first-pass screening tool rather than an individual health diagnosis.
Why doesn't BMI account for muscle mass?
BMI only uses weight and height — it can't distinguish a kilogram of muscle from a kilogram of fat, so a muscular, athletic person can register as "overweight" on BMI despite having low body fat. Body Fat Calculator gives a more direct read on body composition.
Is my numbers uploaded anywhere?
No — BMI Calculator runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.