The Relativistic Energy Calculator computes the total energy of a particle moving at relativistic speeds using Einstein’s formula E=γmc2E = \gamma m c^2E=γmc2, where γ=1/1−(v/c)2\gamma = 1 / \sqrt{1 – (v/c)^2}γ=1/1−(v/c)2​ is the Lorentz factor. By entering the particle’s rest mass and velocity, the calculator accounts for relativistic effects and computes the total energy. This tool is useful for physics students, high-energy particle studies, and understanding energy at speeds close to the speed of light.