DC Motor RPM

Hi,

Is there a way to calculate the RPM of a motor driving a light load based on the supply voltage?

For instance, a 3800KV motor running on 5V would be doing 5*3800 RPM. My guess this is in an unloaded state. Or is that KV rating in all circumstances and does the motor compensate by drawing more current?

Found the answer http://adamone.rchomepage.com/guide5.htm

Excellent site and description of motor principles