Mass-Energy Equivalence Calculator

Calculate energy, mass, or speed of light using Einstein's E = mc². Features mass units (kg, g, mg, µg, lb, amu), energy units (J, kJ, MJ, GJ, eV, keV, MeV, GeV, TeV, kWh), and speed units (m/s, km/s, c). Perfect for physics students studying relativity and nuclear physics.