i pulled out my pie plates yesterday and did a little test: i have 3 different
9" pie plates from different manufacturers (emile henry, le creuset, and unmarked glass). i have always suspected they were different, though all were marked 9".
turns out, they all hold 3 cups liquid, but the glass pie plate is shorter than the others! now i know why my pie crusts are sometimes overflowing when I lay them down, and too short other times: i am making the crust the same size, but using different plates! the emil henry is the tallest, the glass much shorter, by at least 1/4". this absolutely makes a difference! I will no longer do any liquid fillings in the short glass pan (which had the smallest lip and thus, more propensity to spill on the way to the oven)... and by the same token do extra rolling of the crust to make sure it fits when using the emile henry.
"not all pans are created equal"