The unit of measure for energy in the International System of Units (SI) is the joule (J). This unit quantifies energy in various forms, including kinetic, potential, thermal, and electrical energy. The joule is defined as the amount of energy transferred when a force of one newton acts over a distance of one meter, making it a fundamental concept in physics and engineering. Understanding energy measurements is critical for various scientific calculations and applications, enabling analyses of energy efficiency, work done, and the conservation of energy in systems.