Gravitational potential energy is the energy an object possesses due to its position in a gravitational field. It is calculated based on the mass of the object, the height above a reference point, and the acceleration due to gravity (usually 9.81 m/s² on Earth). The formula for gravitational potential energy is PE = mgh, where PE is potential energy, m is mass, g is acceleration due to gravity, and h is height. This form of energy is crucial in various physical processes, such as motion and conservation of energy.