There is no direct comparison, different motors of the same wind can give different kV figures depending on magnet strength or thickness of windings.
The simplest way of having a good idea of what kV rated motors are most likely to be is to check
Novaks motor comparison chart. They list the wind and kV rating of every motor they sell so you should be able to cross reference the listed specs with the kV ratings on your motors to give you an idea of what they should be.