BMI Calculator – Calculate Your Body Mass Index
Enter your height and weight to get your BMI, WHO category and healthy range — instantly, in your browser.
About BMI Calculator
Body Mass Index (BMI) is a quick health screening number calculated from your height and weight. Our free BMI calculator uses the standard WHO formula — weight in kilograms divided by height in meters squared — and instantly shows your BMI value, category (underweight, normal, overweight, obese) and healthy weight range, whether you are checking your BMI as a man or a woman.
📖 The Full Guide
Learn what BMI is, how it is calculated, what a healthy BMI range looks like, and when the number can mislead you — with a free instant BMI calculator.
Read the article →⚖️ BMI Calculator
History
How to Use
Enter your height in centimeters.
Enter your weight in kilograms.
Click Calculate for your BMI and category.
Export, print or share your result.
Frequently Asked Questions
BMI (Body Mass Index) = weight (kg) ÷ height² (m). It is a quick health screening tool that estimates whether your weight is healthy for your height.
According to the WHO, a BMI of 18.5–24.9 is considered a normal/healthy weight. Below 18.5 is underweight, 25–29.9 overweight, and 30+ obese.
BMI is a screening tool, not a diagnosis. It doesn't distinguish muscle from fat, so athletes may show a high BMI while being very healthy.
The same formula is used for both, but women naturally carry more body fat than men at the same BMI, so results should be interpreted with that in mind.
The same WHO ranges apply to both: 18.5–24.9 is healthy for adult men and women. Muscle mass can raise BMI in athletes, so interpret the number with context.
Convert weight to kg (pounds × 0.4536) and height to meters (inches × 0.0254), then use weight ÷ height². Our calculator accepts cm and kg for simplicity.
The Formula
BMI is calculated as weight in kilograms divided by the square of height in meters. The result places you in a WHO category used worldwide for health screening.