Offroad-Express

hey guys, i have a set of hilux diffs for sale, people keep asking me what ratio they are.
i know i need to mark the input and hub, and turn the input untill the hub has done a full revolution, while counting how many times the input has turned!
and i then have to divide or multiply????? im stuck on this bit any help would be grate!

Count the teeth on the crownwheel and count the teeth on the pinion.
Divide the crownwheel teeth by the pinion teeth and that is your diff ratio.