calculates the number of inhabited planets and advanced civilizations that currently exist in our galaxy, based on your own specifications and assumptions. E.T. Counter relies on estimated percentages, probabilities, and average values. The algorithm is inspired by Isaac Asimov's book "Extraterrestrial Civilizations" and the Green Bank formula (mainly created by F. D. Drake).
The first step involves entering assumptions regarding the number of stars in our galaxy and the percentage of stars that have planets, and are part of a multiple star system. The next step requires you to enter the percentage of dwarf stars, sun-like stars, and giant stars; and the probablity that a sun-like star has a suitable ecosphere in case. The third step involves specifying estimates such as the number of sun-like stars, with at least one planet and a suitable ecosphere. The final step requires you to enter assumptions such as the number of currently inhabited planets in our galaxy, when first life forms appeared, and when advanced civilizations appeared.
E.T. Counter then takes your settings, and produces a calculation of the number of currently inhabited planets in our galaxy, the average distance between neighboring inhabited planets, the number of currently existing advanced civilizations in our galaxy, the average distance between neighbouring civilizations, and the number of advanced civilizations in the universe.