Coulomb's Potential Energy Calculator

This calculator finds the electric potential energy stored between two point charges, the energy tied up in their electrostatic interaction. Just as lifting a mass against gravity stores gravitational potential energy, bringing two electric charges near each other stores electric potential energy, the work done to assemble them from far apart. For two point charges it is given by Coulomb's constant times the product of the charges divided by their separation, a close cousin of the force law but with distance to the first power rather than squared. The sign carries real meaning: like charges have positive potential energy, because work must be done to push them together against their repulsion, while opposite charges have negative potential energy, since they attract and energy is released as they come together. This quantity is fundamental to understanding atoms, molecules, capacitors and any system of charges. This tool computes it. You enter the two charges in coulombs, using scientific notation for the usually tiny values, and the distance between them, and the calculator returns the potential energy in joules, the force between the charges for context, whether the interaction is attractive or repulsive, and Coulomb's constant. The results update as you type. Use it for physics study, for electrostatics problems, or to understand the energy in a configuration of charges. The relationship to the force is neat: the potential energy is the force times the distance, since the force follows an inverse-square law and the energy an inverse-distance law. A positive result means energy is stored in pushing like charges together; a negative result means energy would be released as opposite charges attract. Remember that real charges are usually small fractions of a coulomb, so microcoulombs and the scientific-notation input are the norm here.

Potential energy = k x q1 x q2 / r, with k = 8.988 x 10^9. Like charges give positive energy (repulsive); opposite charges give negative (attractive). Use scientific notation for small charges.