2020AJ....159..228G

A scale is described for classifying civilizations according to the amount of power they produce, using the whole numbers 0 through 4 to denote 10⁶, 10¹⁶, 10²⁶, 10³⁶, and 10⁴⁶ W corresponding to the approximate power available at physical scales biological, planetary, stellar, Galactic, and observable universe, extending a Roman numeral scheme introduced by Kardashev and updating it with suggestions from Sagan and Lemarchand including using Arabic numbers to permit decimal subdivisions. Terrestrial civilization circa 2015 would be classified as Type 0.72 on this extended and updated scale. Similar scales can be used to classify information stored, population, and mass of constructions.