The problem is that you need to know what the EVs are to figure out the IVs, and vice versa. You input 0 EVs to find out the IVs when you obviously got some somewhere so that's why it doesn't look right.
And btw, EVs don't pass down through breeding, battling Pokemon give you different EVs in different amounts according to the Pokemon you battle. For example, Audino gives 2 HP Evs every time you defeat one. :]
Source: Experience and I tested it on Showdown ;)