Compute the stored energy of a raised mass in a gravitational field.
Gravitational potential energy is the energy stored in an object because of its position in a gravitational field. Near the Earth's surface it is given by U = mgh, where m is the mass, g the gravitational acceleration, and h the height above a chosen reference level. Lifting an object higher stores more energy, which can later be released as kinetic energy when it falls.
Only changes in height carry physical meaning, so you are free to choose where h = 0. This calculator measures height from that reference and returns the stored energy in joules. Energy conservation links this potential energy to the kinetic energy an object gains as it descends.
It depends on the chosen reference level. Below your zero point, the potential energy is negative; the physically meaningful quantity is the difference between two heights.
It converts into kinetic energy. Ignoring friction, the kinetic energy at the bottom equals the potential energy lost.