Orbital Period Calculator
Orbital Period
Calculate the orbital period of a satellite or planet using Kepler third law
km
kg
Formula
T = 2 x pi x sqrt(a^3 / (G x M)) where a = semi-major axis, M = central body mass
Frequently Asked Questions
What is Kepler third law?
Kepler third law states that the square of the orbital period is proportional to the cube of the semi-major axis: T squared = (4 pi squared / GM) x a cubed.
What is the orbital period of the ISS?
The International Space Station orbits at about 408 km altitude with a period of approximately 92 minutes or about 1.5 hours.