Free Drake Equation Calculator

Estimate the number of detectable civilisations in the Milky Way using the Drake equation: N = R* * fp * ne * fl * fi * fc * L.

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Detectable Civilisations (N)

0.04

Detectable Civilisations (N) vs Civilisation Lifetime (L)

The Drake Equation

N = R* × fp × ne × fl × fi × fc × L

  • R* = rate of suitable star formation (stars/year)
  • fp = fraction with planetary systems
  • ne = habitable planets per system
  • fl = fraction where life develops
  • fi = fraction developing intelligence
  • fc = fraction developing detectable technology
  • L = years a civilisation remains detectable
  • Formulated by Frank Drake in 1961, this is a framework for thinking about extraterrestrial intelligence, not a precise prediction. Estimates of N range from less than 1 to millions.

    Example Calculation

    Moderate estimates for each parameter.

    1. 01N = 1.5 × 1.0 × 0.2 × 0.13 × 0.01 × 0.01 × 10000
    2. 02= 1.5 × 0.2 × 0.13 × 0.01 × 0.01 × 10000
    3. 03= 1.5 × 0.2 × 0.13 × 1 = 0.039
    4. 04N ≈ 0.039 (suggests we may be alone in the Galaxy with these values)
    5. 05Adjusting L to 1 000 000 years gives N ≈ 3.9

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