Since the 1990s, the high consumption of electrical energy has become an indispensable point for economic development, which has resulted in major environmental impacts due to the construction of new options of obtaining electrical energy. Given this, the search for conscious consumption is of paramount importance for there to be harmony between the development process and the environment. In other words, monitoring energy consumption and the amount spent in real time becomes a crucial factor. Thus, the present work consists of the development of a three-phase prototype for monitoring electricity consumption in real time, which allows the consumer to be able to have an estimate of their spending instantly, using non-invasive sensors in conjunction with the Arduino platform. The prototype provides the values obtained on an LCD display, informing the voltage and current measurements in the three phases of the system, the total monitoring time, the energy consumed and, finally, the approximate cost to be paid by the consumer. The results obtained were satisfactory, since the measured values are in accordance with the input signals and the calculated values are close to those calculated theoretically.