BMI Calculator
Calculate your Body Mass Index (BMI) using metric or imperial units. Includes the WHO weight category for adults.
Your measurements
How to use this calculator
1. Choose your unit system
Toggle between metric (kg / cm) and imperial (lb / ft·in). Your inputs convert automatically when you switch — no manual conversion needed.
2. Enter weight and height
Use your current measurements. For most accurate results, measure first thing in the morning before eating or drinking.
3. Read the result and the bar
The colored bar shows where you fall on the standard adult BMI scale. The bottom card tells you how many kilograms (or pounds) from the healthy range, if any.
When BMI doesn't tell the whole story
BMI ignores body composition. A very muscular person can register as "overweight" while being lean and healthy; someone with low muscle mass can fall into "normal" while having unhealthy body fat. Use it as a starting point, not a diagnosis.
About BMI
What is BMI?
BMI (Body Mass Index) is weight (kg) divided by height (m) squared. It's a quick screening tool — not a diagnosis. A high BMI may suggest higher body fat, but BMI doesn't measure body fat directly.
WHO categories (adults 20+)
Underweight < 18.5 · Healthy 18.5-24.9 · Overweight 25-29.9 · Obese ≥ 30. These are guidelines; talk to a healthcare professional for a complete picture.
Why isn't BMI perfect?
It can misclassify very muscular people as overweight and overlook excess fat in people with normal weight. Waist-to-hip ratio and body fat percentage are useful complements.