Orbital Period Calculator – Calculate Celestial Body Revolution Times

Use this orbital period calculator to quickly determine the time it takes for an object to complete one orbit around another body.

Orbital Period Calculator

Use this tool to calculate the orbital period of a satellite around a central body based on its semi-major axis and the mass of the central body.

How to Use the Calculator

Enter the semi-major axis and the mass of the central body in the respective input fields and click “Calculate”. The orbital period will be displayed in seconds.

How it Calculates the Results

The calculator uses Kepler’s Third Law of Planetary Motion, which relates the orbital period to the semi-major axis and the mass of the central body:

P2 = (4π2 * a3) / (G * M)

where P is the orbital period in seconds, a is the semi-major axis in meters, M is the mass of the central body in kilograms, and G is the gravitational constant (6.67430 x 10-11 N*(m/kg)2).

Limitations

This calculator assumes a two-body system and does not account for perturbations caused by other bodies. It is not accurate for systems that are influenced by multiple gravitational forces or for highly elliptical orbits where the semi-major axis does not well-define the orbit’s size.