text: how fast is the earth rotating on its axis?   firstly 1 day per revolution strictly isn't 24 hours since one revolution is completed in 23hours 56minutes giving us the leap year phenomenon.  it takes 23 hours 56 minutes and 4.09 seconds for the earth complete on revolution.  86164.09 seconds in total.  radians per second is the standard measurement for angular momentum (speed). the si unit for this is rad.s^-1  earths angular momentum = 2π/86164.09s = 7.2921159 x 10^-5 rad/s  if you want to know the avarage speed expressed in distance over time you need to find the circumference of the earth of your location. lets use the equator as an example which is aprox 40076km.  40076km x 1000 {convert to meters} = 40076000m  40076000m/86164.09s  = 465.11255 m/s (meters per second) = 1674 km/s (kilometers per hour) = 1047 miles per hour   if you want to know the spesific speed for you location find the latatude on a map and substitute   circumference = 2 pi r cos(x), where  pi = 3.14159... r = the earth's equatorial radius = 6378km  x = the angle of latitude. (your location on map)  now multiply your answer by 1000 to get distance in meters and devide by 86164.09 to get the speed in meteres per second.