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Calculate your Body Mass Index with age and sex for a clearer, more personal reading of your weight.
BMI relates your weight to your height. Add your age and sex and we also estimate your body-fat percentage, then plot the result on a visual scale so you can see exactly where you land.
Body Mass Index is the most widely used way to check whether your weight sits in a healthy range for your height. This calculator goes a step further than a plain BMI number: by adding your age and sex it also estimates your body-fat percentage and shows exactly where you fall on the healthy-weight scale.
Use it as a quick screen, not a diagnosis — muscle, frame size and age all affect what a given number means for you.
BMI is a simple ratio of weight to height, with a body-fat estimate layered on top.
BMI = weight(kg) / height(m)²BMI = 703 · weight(lb) / height(in)²BF% = 1.2·BMI + 0.23·age − 10.8·sex − 5.4sex = 1 for male, 0 for female (adult estimate).BMI itself only uses height and weight, but age and sex let us estimate your body-fat percentage and interpret the number more accurately. At the same BMI, body fat tends to be higher with age and higher for women than men.
BMI is a population screen, not a diagnosis. It can overestimate body fat in muscular people and underestimate it in older adults. The body-fat estimate helps, but treat both as a starting point.
For most adults a BMI between 18.5 and 24.9 is considered the healthy range.