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Home: The Kardashev scale

How the figure is calculated

Each type is a level of power, the energy a civilization uses each second, measured in watts. Carl Sagan's 1973 version of the scale sets Type I at 10^{to the power 16} W and fills in the steps between the types, with each step of 0.1 meaning ten times the power.^{Source 2,Source 3} Humanity used an average of 1.9 × 10^{to the power 13} W in 2025, or 19 trillion watts, roughly one five-hundredth of Type I, which places humanity at 0.73.^{Source 4} The figure is recalculated each year when the Energy Institute publishes its Statistical Review of World Energy.

1. N. S. Kardashev, Transmission of Information by Extraterrestrial Civilizations, Soviet Astronomy 8, 217, 1964, p. 219.
2. C. Sagan, The Cosmic Connection: An Extraterrestrial Perspective, Doubleday, 1973 (Cambridge University Press edition, 2000, p. 234).
3. R. H. Gray, The Extended Kardashev Scale, The Astronomical Journal 159, 228, 2020, equation 1 and table 2.
4. Energy Institute, Statistical Review of World Energy 2026, total energy supply table, p. 23.

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