Alter any of the values found in the drake equation to see how it affects the total number of civilizations in which humans could communicate within our own galaxy.

Drake Equation Formula

The following equation is used to calculate the theoretical number of civilizations that humans could communicate with within the Milkyway Galaxy.

N = R * fp * ne * f1 * fi * fc *L
  • Where N is the number of civilizations humans could communicate with
  • R is the mean rate of star formation.
  • fp is the fraction of stars that have planets
  • ne is the average number of planets that could support life per star with planets
  • f1 is the fraction of life-supporting planets that develop life
  • fi is the fraction of planets with life where intelligent life develops
  • fc is the fraction of intelligent civilizations that develop communication
  • L is the length of time that civilizations can communicate (years)

What is the Drake Equation?

The drake equation is a theoretical equation developed by Dr. Frank Drake in 1961. This equation attempts to calculate the number of civilizations that humans could possibly communicate with given the factors presented in the equation.

Sounds great, but what’s the problem? The problem is that none of the factors present in the equation have been definitively solved for in Astrophysics. Some have more evidence than others, but none have values that are considered fact. In that regard, the equation itself is only a fun thought experiment at the moment. If some of these factors could be proved or calculated, then the equation could be simplified.

What are the current estimates for the Drake Equation factors?

The following list describes the current estimates for the factors presented above:

  • R* = 1.5-3 stars per year
  • fp = .95-1
  • ne = .4
  • f1 = .90-1
  • fi = .75-1
  • fc = .50
  • L = 402 years
Drake Equation Calculator
drake equation formula