gear ratio help!

MoparDaddy said
Here's an ignorant question for everyone that I've forgotten the answer to. Without pulling the diff cover, how do you calculate your gear ratio? Jack up the rear end and spin the tire, ect. I don't remember the details

Pretty sure its one spin of the tire to the amount of spins of the yoke of the pig

(For example about 3.25 yoke turns to one tire spin would be 3.23s and so on)