The boarding house business is increasingly growing, especially in areas with many universities, such as Ponorogo. However, challenges arise when boarding house owners set the same electricity rental rate for each tenant, even though electricity consumption varies. This results in dissatisfaction among tenants and potential losses for the owners. This research aims to design an Internet of Things (IoT)-based electricity usage monitoring system to address this issue. The system developed uses a PZEM sensor to measure current and voltage, as well as an ESP 8266 to access data via MySQL web, which is displayed on a web page. The research results show that this system is capable of providing real-time monitoring of electricity usage, including current, voltage, power, and energy, allowing the owner to calculate costs based on the actual consumption of each room. Moreover, tenants become more aware of their electricity usage, encouraging more prudent energy management. System evaluation demonstrates performance aligned with the initial plan, with the ability to reduce the risk of electrical circuit overload. Thus, this research provides a fairer and more effective solution for managing electricity usage in boarding houses and supports sustainability in energy management.