Orbital Period (Kepler)
Find the orbital period and speed of a satellite or planet from its orbit radius around the Sun, Earth, Moon, Mars or Jupiter, free online.
About this calculator
Kepler's third law for a circular orbit gives the period T = 2ฯโ(aยณ รท GM) and the orbital speed v = โ(GM รท a), where a is the distance from the centre of the central body. For a satellite, add the planet's radius to its altitude.