Calculate your Body Mass Index (BMI) instantly with metric or imperial units and see your weight category.
Body Mass Index (BMI) is a simple ratio of your weight to your height. It gives a quick estimate of whether you fall into the underweight, normal, overweight, or obese range. Because it takes seconds to calculate and needs no special equipment, BMI is one of the most widely used screening tools in health and fitness.
The formula is your weight in kilograms divided by your height in metres squared. Our calculator does this automatically and even converts imperial units for you, so you can focus on the result rather than the math.
If you lift weights seriously, take your BMI result with a grain of salt. BMI cannot tell the difference between fat and muscle. A muscular athlete may register as "overweight" or even "obese" despite carrying very little body fat. That is why we recommend pairing BMI with our Body Fat Calculator, which gives a far more useful picture of your actual composition.
BMI is a starting point, not a verdict. Use it alongside body-fat percentage and progress photos for the full story.
Think of BMI as one data point among several. If your number is high but you train hard and carry visible muscle, your body-fat percentage matters more. If your number is high and you are relatively untrained, it may be a signal to dial in your daily calories and start a structured program. Either way, consistency in training and nutrition beats any single number on a chart.