A universal energy law is proposed in the form of a formula that includes the energy constant and dimensionless parameters. This way of representing the energy formula is a generalized equation for mechanical, electric, magnetic, gravitational and thermal energy. From one generalized energy equation directly follows: kinetic energy formula E=mV^2/2, quantum energy formula E=hν, Einstein formula E=mc^2, thermal energy formula E=3kBT/2, Joule-Lenz law, gravitational energy formula, electrical energy, magnetic energy, charged capacitor energy, inductance coil energy, rotational kinetic energy. The universal energy formula includes a single energy constant (Eo = 8.18710577... x 10^-14 J). The energy constant is numerically equal to the resting energy of the electron. Despite the electromagnetic status of this constant, it is a constant not only in the laws of electromagnetic energy, but also in the laws of mechanical energy, gravitational energy, and thermal energy. The dimensionless quantities are represented by the ratio of the used characteristics to the constants of these characteristics. The Universal formula of energy will facilitate the study and understanding of the laws of mechanics, gravitation and electromagnetism in the educational process.