Which unit is electric potential energy measured in?

Electric potential energy is measured in joules because it is a measure of the work done in moving a charge within an electric field. The joule is the standard unit of energy in the International System of Units (SI), and it quantifies energy, work, and heat.

In contrast, volts measure electric potential (the potential energy per unit charge) rather than energy itself. Watts represent power, which is the rate at which energy is transferred or converted, and amperes measure electric current, which relates to the flow of electric charge. Therefore, while volts, watts, and amperes are all essential quantities in electrical systems, it is joules that specifically indicate electric potential energy.