Thought some people might find this useful. I am working on a project that must switch a MOSFET at very high speed. The power budget for the control circuitry is very very small, so the power required to drive the mosfet (gate) is actually a concern.
I did a little searching and found a supertex application note that describes exactly how to (accuratly) calculate the total power and average current required to switch a mosfet at a frequency.
Hope this helps someone...http://www.supertex.com/pdf/app_notes/AN-H21.pdf