The SBMI calculator functions on the basis of the newly developed Smart Body Mass Index. The SBMI differs from the BMI in three important aspects. Firstly, it takes age and sex into account, besides weight and height. Secondly, the SBMI is a purely comparative figure (without any physical units) on a scale of 70 points. And thirdly, the significance of the body weight for your health can easily be derived from the SBMI but not from the BMI: The weight-related health risk levels shown in green, yellow, orange and red (see the SBMI chart
Source: What is the SBMI?