All human work and needs are very dependent on the existence of electrical energy, especially household needs. Human negligence in the use of electrical energy will lead to waste which also has an impact on increasing the cost of using electrical energy. This monitoring tool uses the NodeMCU ESP8266 module, relay, 12 V adapter, Digital kWh Meter, LM2596 IC, PZEM-004T voltage and current sensors. The control center on the monitoring device uses the NodeMCU ESP8266 module, measures voltage and current values using the PZEM-0047 sensor. Data from sensor readings is then processed using IOT Blynk with an internet connection, then generates values for measuring voltage, current, power and cost. The percentage of errors is approximately 0.4% and 0.32% for all data calculations, there is a 15 second delay for sending data from sensors to IoT Blynk

Keyword: Blynk, NodeMCU, Sensor PZEM-0047