The bioimpedance analysis is a technique used with a small alternating current to determine the impedance that is the human body's opposition to the electric current. The bioelectrical impedance analysis equipment, which currently exists, is not prepared to be used in under-ten children, since they do not have the necessary formulas to perform the calculations, which is why in this project it is demonstrated by making use of electronic circuits and microcontrollers, that it is possible to make an analysis of electric impedance in under-ten children, thanks to the development of a device through which it is possible to estimate the impedance of the human body and with this it was possible to find the percentage of body fat, in addition to parameters such as lean mass (mass that is not fat), fat mass, total water and body mass index.