The BMI (Body Mass Index) calculator is a tool used to assess an individual's body weight relative to their height. It provides an estimate of whether a person has a healthy body weight and whether they are underweight, overweight or obese. The calculation is made by dividing a person's weight in kilograms by the square of their height in meters (kg/m²).

BMI calculators are widely used in healthcare to screen for potential weight-related health problems. It is a free app and very easy to use.