Planets - Calculate Orbital Velocity

Calculator for the mean orbit velocity of a planet orbiting the Sun and of the Moon orbiting Earth, in different units and compared to each other. A celestial body, orbiting another one, must have a certain velocity to stay in a stable orbit. The average orbital speed results from the mass of the central body (the Sun, or in case of the Moon, it is Earth), the mass of the orbiting body and from the semimajor axis of the orbit (the smaller the semi-axis, the higher is the velocity). Therefore, Mercury is the fastest planet and Moon is much slower than the planets.

Kilometers per hour:
Meters per second:
Miles per hour:
Orbital velocity		km/h m/s mph
Mercury:
Venus:
Earth:
Mars:
Jupiter:
Saturn:
Uranus:
Neptune:
Pluto:
Moon-Earth:

Round to   0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15   decimal places.

Please enter one value, the other values will be calculated.

Example: Mercury has more than ten times the orbital velocity of Pluto and 46 times that of the Moon with its only 1 kilometer per second.

Speed or velocity is of course calculated as distance divided by time. The distance, the planet's orbit around the star or the moon's orbit around the Earth, forms an ellipse. The time required for one orbit is determined by Kepler's 3rd law.

We inhabitants of Earth usually do not notice this orbital speed. The fact that this speed is enormously high, exceeding 100,000 kilometers per hour, becomes apparent only when the Earth collides with something. In most cases, these objects are dust grains measuring a millimeter or less, which appear as shooting stars as they burn up in the atmosphere. The high speed causes the air in front of the meteoroid to be intensely compressed and heated. This heat causes the meteoroid itself to burn up, leaving only tiny remnants to drift down to the ground. Larger chunks can make it through. They generate an intense glow as they travel through the atmosphere and can cause significant damage upon impact with Earth. The high energy released during such events stems from two factors, the Earth's orbital speed and the object's own velocity, which may be higher or lower.

Last updated on 08/07/2026. Author: Jürgen Kummer

Calculators for Planets and Astronomy

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