Work out geostationary orbit instantly with clear inputs, formula shown and shareable results.
A geostationary satellite must orbit with a period equal to the sidereal day of 23h 56m 4s, which puts it at 42,164 km radius or 35,793 km altitude, moving at 3.07 km/s. From there it sees about 162 degrees of longitude, so three satellites can cover the whole equatorial belt - the basis of global broadcast and weather coverage.
Geostationary radius
a = cbrt(GM T(sidereal)^2 / 4 pi^2)
Visible longitude span
2 arccos(R / a)
Because the satellite must match Earth's rotation against the stars. Using 24 hours would put it about 80 km too high and let it drift.
Any inclination makes the satellite oscillate north and south of the equator daily, so it is geosynchronous but not geostationary.