Orbital Velocity Calculator
Calculate the speed needed for a circular orbit at a given altitude.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Orbital Velocity Calculator
Enter the central body mass and orbital radius. The calculator gives you the velocity needed for a stable circular orbit.
- Enter central mass. For Earth, use 5.972 x 10^24 kg.
- Enter orbital radius. Measure from the center of the body, not from the surface. For low Earth orbit, add about 400 km to Earth's radius.
- Read the result. Orbital velocity appears in m/s and km/s.
About the Orbital Velocity Calculator
Orbital velocity is the speed at which an object must travel to maintain a stable circular orbit around a massive body. At this speed, the gravitational pull exactly provides the centripetal force needed for circular motion. The International Space Station orbits at about 7,660 m/s (27,600 km/h) at an altitude of roughly 400 km. Lower orbits require higher speeds, while higher orbits are slower. The formula v = sqrt(GM/r) comes from equating gravitational force to centripetal force.
Frequently Asked Questions
What is the orbital velocity of the ISS?
The International Space Station orbits at approximately 7,660 m/s (about 27,600 km/h) at an altitude of roughly 400 km above Earth.
Does orbital velocity depend on the satellite's mass?
No. Orbital velocity depends only on the central body's mass and the orbital radius, not on the orbiting object's mass.
What happens if you go faster than orbital velocity?
If you exceed circular orbital velocity, the orbit becomes elliptical. If you reach escape velocity (sqrt(2) times orbital velocity), you leave the gravitational field entirely.