Satellite Velocity Calculator

Enter your satellite's orbital altitude above Earth's surface and get the orbital speed and orbital period calculated instantly. The Satellite Velocity Calculator uses the standard gravitational formula — v = √(GM/r) — to find how fast a satellite must travel to maintain a stable circular orbit. You also get the orbital period (how long one full revolution takes) broken down in minutes, hours, and days.

km

Height of the satellite above Earth's mean sea level. LEO is ~160–2000 km; GEO is ~35,786 km.

Select the body at the center of the orbit.

Results

Orbital Speed

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Orbital Speed

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Orbital Radius from Earth's Center

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Orbital Period

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Orbital Period

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Orbital Period

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Orbital Speed vs. Altitude Comparison

Results Table

Frequently Asked Questions

What formula is used to calculate orbital speed?

The orbital speed is calculated using the formula v = √(GM / r), where G is the gravitational constant (6.674 × 10⁻¹¹ N·m²/kg²), M is the mass of the central body, and r is the orbital radius (planet radius + altitude). This formula assumes a circular orbit.

How do you calculate the orbital period of a satellite?

The orbital period T is calculated as T = 2π × r / v, which is equivalent to T = 2π × √(r³ / GM). For a low Earth orbit satellite at ~400 km altitude, the period is approximately 92 minutes.

What are Earth's satellites?

A satellite is any object that orbits a larger body. Earth's natural satellite is the Moon. Artificial satellites are spacecraft launched into orbit for purposes such as communication, navigation (GPS), weather monitoring, and scientific research. Sputnik 1 was Earth's first artificial satellite, launched in 1957.

What determines the orbital speed of a satellite?

Orbital speed depends on the mass of the central body and the orbital radius. The higher the altitude, the lower the required orbital speed. For Earth, a satellite at 400 km needs ~7,672 m/s, while a geostationary satellite at 35,786 km only needs ~3,075 m/s.

What is the difference between LEO, MEO, and GEO orbits?

Low Earth Orbit (LEO) is between 160–2,000 km altitude. Medium Earth Orbit (MEO) ranges from 2,000–35,786 km and is used by GPS satellites. Geostationary Earth Orbit (GEO) is at exactly 35,786 km, where the orbital period matches Earth's rotation, so the satellite appears stationary above one point.

Why does orbital speed decrease as altitude increases?

At higher altitudes, gravity's pull is weaker, so less centripetal force — and therefore less speed — is needed to maintain a stable orbit. The relationship is an inverse square root: doubling the orbital radius reduces the speed by a factor of √2.

Can this calculator be used for satellites orbiting other planets?

Yes. By selecting a different central body (Moon, Mars, Jupiter, etc.), the calculator uses that body's gravitational parameter (GM) and radius to compute the correct orbital speed and period for any circular orbit around it.

What happens if a satellite travels too fast or too slow?

If a satellite moves too fast, it escapes orbit and flies off into space. If it moves too slow, gravity overcomes the orbital momentum and the satellite spirals down and re-enters the atmosphere. The precise orbital speed is the balance point where gravitational pull exactly provides the centripetal force needed for circular motion.

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