Medical scales are used in doctors offices to measure a persons weight as well as their height. These scales come in many different styles and sizes and have many different features on them. The basic medical scale is an upright bar scale with mechanical functions. A sliding calibrator is used to measure a persons weight. These types of scales are very accurate and are the most common scale found in a doctors office or even a hospital setting. Another type of scale is the digital scale. These scales give the weight of an individual but also give out other valuable information useful to the doctor. This includes the BMI or body mass index of a person. The BMI is the per cent of body fat found on the body. Medical digital scales typically are flat and have a LCD display on them. Digital scales work well but most doctors prefer using bar scales saying that they are much more accurate.