BMI Calculator
Calculate your Body Mass Index (BMI).
🔒 Runs entirely in your browser — nothing is uploaded.
ℹ️ BMI is a rough screening measure, not a diagnosis - it doesn't account for muscle mass, frame, or body composition. Consult a healthcare professional for medical advice.
Your BMI
How BMI Calculator works
How is my BMI actually calculated here?
This calculator uses the standard weight / height² formula. In metric mode that's kilograms divided by height in meters squared; in imperial mode it applies the conversion 703 × pounds / inches², so you get an equivalent result without converting units yourself. The output is then mapped into one of four categories: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), or obese (30 and above).
When should I use a BMI calculator?
It's a fast way to get a general sense of whether your weight falls in a typical range for your height, useful as a starting point before setting a fitness or nutrition goal. Many people also use it to track how the number shifts over months of diet or training changes, though the trend matters more than any single reading.
What are the limits of BMI as a measurement?
BMI only uses weight and height, so it can't distinguish muscle from fat - a muscular athlete and a sedentary person of the same height and weight get identical scores. This tool is for general screening only and isn't medical advice; a healthcare professional can assess body composition and health risk far more accurately.