Drake Equation
N = R⋅fp⋅ne⋅fl⋅fi⋅fc⋅L (your parameter guesses).
Inputs
Results
N
20
log₁₀ N1.301
How to Use This Calculator
- Enter the star formation rate R* (stars/yr) -- current Milky Way estimate is ~3 stars/yr.
- Set fractions: f_p (planets per star), n_e (habitable planets per system), f_l (life emergence), f_i (intelligent life).
- Enter the fraction developing communicating technology (fc) and civilization longevity in years (L).
- Review the estimated number of communicating civilizations (N) in the galaxy and its log10 value.
- Explore how varying L (from decades to millions of years) dominates the uncertainty in N.
How the result changes with R* (stars/yr)
| R* (stars/yr) | N |
|---|---|
| 100 | 1,000 |
| 350 | 3,500 |
| 650 | 6,500 |
| 900 | 9,000 |
What each input means
- R* (stars/yr)
- Star formation rate suitable for planets.
- f_p
- Fraction with planets.
- n_e
- Habitable planets per star.
- f_l
- Life develops.
- f_i
- Intelligence.
- f_c
- Detectable tech.
- L (years)
- Communicating lifetime.
How this is calculated
Formula
N = R★ × fp × ne × fl × fi × fc × LRelated Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Astrophysics & Astronomy
Escape Velocity Calculator
Calculate escape velocity, orbital velocity, and gravitational parameters for celestial bodies.
Astrophysics & AstronomyOrbital Period Calculator
Calculate orbital period using Kepler's laws. Find orbital velocity, angular velocity, and perihelion/aphelion distances.
Astrophysics & AstronomyStellar Luminosity Calculator
Calculate stellar luminosity using Stefan-Boltzmann law. Find absolute magnitude, main sequence lifetime, and stellar parameters.
More in Science & Physics.