Habitable Zone Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026Finding the "Goldilocks zone" around a star
The habitable zone is the orbital distance range where a rocky planet could plausibly maintain liquid water on its surface, based purely on the amount of energy it receives from its host star.
Worked example
For a star with the Sun's exact luminosity (1.0 solar luminosities):
Inner Edge = sqrt(1.0/1.1) = 0.953 AU
Outer Edge = sqrt(1.0/0.53) = 0.953 - 1.374 AU
Earth orbits at exactly 1.0 AU, comfortably within this calculated range for our Sun - confirming the formula lines up with Earth's own well-established position in the solar system's habitable zone.
This is a simplified estimate based on stellar energy alone - actual habitability depends on many additional factors including atmospheric composition, planetary mass, magnetic field, and axial tilt, none of which this simplified model accounts for.