How many inches of pea gravel should I have in my well window?

Answer 1

The gravel act as a drain to keep the well from filling during rains and leaking through the window. Deeper is better in this case.

Answer 2

well sorry this isn't really the answer your looking for but if your doing the work of it I think you would like to do it right.
http://www.basementsystems.com/basement_waterproofing/basement_window/window_well.php

Check that out I have done window wells the other way and wouldn't do it that way again