Exoplanet Discovery Calculator

Find the transit depth a planet produces crossing its star.

Transit depth (%) 0.0084

Transit depth (ppm) 83.709

Formula: depth = (R_planet ÷ R_star)²

Step-by-step with your numbers:

1. Values used:

2. Planet radius = 1 R⊕

3. Star radius = 1 R☉

5. Transit depth = 0.0084%

6. Transit depth = 83.709ppm

Did we solve your problem today?

The transit method finds planets by the tiny dip in starlight as they pass in front.

The math behind it

Transit depth = (R_planet ÷ R_star)², the fraction of the star's disk the planet blocks.

An Earth across a Sun-like star → about 84 ppm (0.0084%).

Why are Earth-like planets hard to find?

Their transit signal is minuscule — under 100 parts per million.