Gutenberg and Richter (1955) revised the magnitude-energy relation for earthquakes. They found discrepancies among magnitudes derived from local earthquakes (ML), body waves (MB), and surface waves (MS). The relation between ML and the others is not yet definitive. The latest revision gives a = 0.37, b = 6.76. They recommend that ML continue to be used as before, but MS (and ultimately ML) should be referred to MB as a general standard, called the unified magnitude and denoted by m. Tentatively, log E = 5.8 + 2.4m (E in ergs). Revised tables and charts for determining m are given. The unified magnitude m is defined as a system of tables and charts for calculating magnitude from the quotient amplitude/period for the maximum waves of the principal wave groups P, PP, and S. The equation log E = 5.8 + 2.4m is used to calculate energy from magnitude. The paper also discusses the energy calculation from seismic waves and the derivation of empirical equations relating magnitude to energy. The unified magnitude m is preferred for teleseisms, and the Richter scale is retained for local shocks. The paper concludes that the unified magnitude m provides a consistent and independent basis for magnitude-energy relations.Gutenberg and Richter (1955) revised the magnitude-energy relation for earthquakes. They found discrepancies among magnitudes derived from local earthquakes (ML), body waves (MB), and surface waves (MS). The relation between ML and the others is not yet definitive. The latest revision gives a = 0.37, b = 6.76. They recommend that ML continue to be used as before, but MS (and ultimately ML) should be referred to MB as a general standard, called the unified magnitude and denoted by m. Tentatively, log E = 5.8 + 2.4m (E in ergs). Revised tables and charts for determining m are given. The unified magnitude m is defined as a system of tables and charts for calculating magnitude from the quotient amplitude/period for the maximum waves of the principal wave groups P, PP, and S. The equation log E = 5.8 + 2.4m is used to calculate energy from magnitude. The paper also discusses the energy calculation from seismic waves and the derivation of empirical equations relating magnitude to energy. The unified magnitude m is preferred for teleseisms, and the Richter scale is retained for local shocks. The paper concludes that the unified magnitude m provides a consistent and independent basis for magnitude-energy relations.