BMI Calculator

Body Mass Index (BMI) is a quick screening number that compares your weight to your height. It divides your weight in kilograms by your height in metres squared, then places the result into one of four ranges.

BMI is useful as a first look, but it doesn't measure body fat directly and ignores muscle mass, bone density, and where fat sits on the body. Athletes can score high from muscle alone, so treat BMI as a starting point rather than a diagnosis.

Body weight also interacts with sleep: excess weight is linked to sleep apnea and fragmented rest, while poor sleep can disrupt the hormones that govern appetite. A healthy weight and good sleep tend to reinforce each other.