Planetary Mass Calculator
Calculate planetary mass using orbital period and semi-major axis
About this calculator
The Planetary Mass Calculator uses Kepler's Third Law to determine a planet's mass based on its orbital characteristics. By inputting the orbital period and semi-major axis of a satellite or moon orbiting the planet, this calculator applies fundamental gravitational principles to compute the central body's mass. This tool is invaluable for astronomers, students, and space enthusiasts studying planetary systems, exoplanets, or conducting orbital mechanics research.
How to use
Enter the orbital period of a satellite or moon in the designated time unit field. Input the semi-major axis (average orbital distance) in the appropriate distance unit. Click calculate to instantly determine the planet's mass using Kepler's Third Law formula, which relates orbital motion to gravitational mass.
Frequently asked questions
What units should I use for orbital period and semi-major axis?
Use consistent units like years and AU, or seconds and meters. The calculator typically accepts multiple unit options for convenience.
Can this calculate mass for any celestial body?
Yes, it works for any central body with orbiting objects, including planets, stars, asteroids, or even artificial satellite systems.
How accurate are the results from this calculator?
Accuracy depends on input precision. Results are highly accurate when using precise orbital data from astronomical observations or space missions.