Satellite Orbit Period & Speed Calculator
Estimate a circular Earth orbit from its height above a mean spherical Earth.
Calculate locally
No account, API or uploaded inputs. All calculations run in this browser.
Allowed: 100 to 1000000.
Circular orbital speedkm/s
Orbital periodminutes
Worked example
At 400 km altitude, radius is 6771.0084 km. The model gives about 7.673 km/s and 92.41 minutes per revolution.
Method and units
Use radius r = 6371.0084 + altitude, in kilometres. Circular speed is √(μ/r); period is 2πr/v. Earth μ = 398600.435507 km³/s².
What this result means
This is a two-body circular model, not an ISS tracker or a prediction of overpasses. It omits atmosphere, Earth oblateness, inclination, eccentricity and manoeuvres. Minimum 100 km is a calculation boundary, not a claim of a stable orbit.