How to use it
Pick your units
Switch between metric (kg and cm) and imperial (lb and inches).
Enter weight and height
Type your current weight and height into the fields.
Read your result
Your BMI and weight category update instantly as you type.
About the BMI calculator
Body mass index is a quick screening number that relates your weight to your height. In metric it is weight in kilograms divided by height in metres squared; in imperial it is 703 times weight in pounds divided by height in inches squared. The standard categories are: under 18.5 underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, and 30 or above obese.
BMI is a general screening tool only. It does not account for muscle mass, body composition, age or sex, and is not a diagnosis. This is for general guidance, not medical advice — talk to a healthcare professional about your health.
Questions
Is anything uploaded?
No for this tool. The calculation runs entirely in your browser and nothing is uploaded.
Does it work on mobile?
Yes. The same workspace adapts to smaller screens and keeps the primary controls visible.
Is BMI a medical diagnosis?
No. BMI is a simple screening estimate and ignores muscle, frame and other factors. For a proper assessment, speak with a healthcare professional.