basic

Kepler's Third Law Orbital Period Calculator

T² ∝ a³ — orbital period from semi-major axis.

Calculates the orbital period of a satellite or planet using Kepler's third law given the semi-major axis and central body mass.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

T = 2π × √(a³ / GM)

In depth

Calculates the orbital period of a satellite or planet using Kepler's third law given the semi-major axis and central body mass.