Hyperturbo calculating equity in all-in

Hey, just a quick question. First hand of a hyperturbo. Both players have t500. I minraise and my oponent shoves.

There is 540 in the pot and I have to call 460. So the equity I need to make the call profitable is 460/1000= 46% ?

Because I just realized that this is very shocking than, as I can very easily calculate the equity everytime there is an all-in situation and all the chips are in the play( we both have 500). It is just taking one decimal place out of your chips, and you have the percentae. Right?

Is there any simmilar easy way to calculate how often he has to fold when I go all-in vs him?