Drainage holes

Hello, So I want to transplant my plants into 4.5 gallon containers but they do not have drainage holes. Hows Many (and what size) drainage holes should I make at the bottom of the container for good drainage if I'm using a 20% perlite soil mixture?

Thanks!

bump, need to know I wanna transplant today

lol, dude as long as water comes out the bottom your fine! lol, size and amount do NOT matter what so ever! lol, as long as the excess water can drain out, your good!

the more the better, mj loves aeration.saw a neat design that adds more air then holes in the bottom. Cut a cup to a 1in or so height and poke many hole in the bottom. Invert the cup into the pot so the bottom with holes is facing up and cover with your medium (creates and air gap in the bottom of the pot). saw it in the hydro store and says its better then drainage holes.