I'm assuming you mean implied odds. Implied odds are a lot trickier than pot odds, because you need to be able to understand the board texture and your opponent's behavior. You also need to factor in stack sizes. The deeper the stacks, the better your implied odds because there is more money.
Say you have
on a board of
Your implied odds here are pretty terrible. It is going to be really obvious when you hit your flush, and it will be hard to get any more money in the pot on the river. You might get a little, if someone thinks you were chasing with a straight draw, but you're not going to get stacks in.
Now, if you have
on a board of
Your implied odds here are going to be a lot better than in the first hand. If you hit a 3 or an 8, both those cards aren't very threatening on this board. You have one less out, but you have better implied odds because your opponent is likely to pay off a bet on the river.
The hard part is that it's impossible to really know how often and how much you will get paid when you hit. It depends on your opponent's range, stack, and tendencies. The stronger your opponent's range, the better your implied odds. The more timid your opponent is (people who fold too much), the worse your implied odds.
Implied odds are more of an art-form than a science. It takes experience to know.
EV [expected value] is the combined value of all possible outcomes of our action. Take the second hand above. And, say the pot is $100 and you and your opponent both have $280 stacks. Your opponent bets $60. The EV of folding is $0. The EV of calling is trickier.
38 times out of 46, you miss the river. We'll assume that you lose every time this happens.
38/46 * -$60 ~= -$49.57
If you call the pot will be $220 and the stacks will be $220. We will assume that 40% of the time you're able to get stacks in. 30% of the time your opponent will make a bet of $80 and fold to a raise. And the rest of the time you get no more money.
8/46 * 40% * $380 ~= $26.43
8/46 * 30% * $240 ~= $12.52
8/46 * 30% * $160 ~= $8.35
If we add all these values up, 26.43+12.52+8.35-49.57, we get -$2.27. This means we expect our call to have a negative value, and folding looks to be better than calling. We can do the same thing for trying to figure out the EV of raising.
It should be noted that we made some assumptions about how our opponent would play when we hit (this is more of that implied odds stuff). It is important to not be overly optimistic when using implied odds. Still if the stacks were deeper here, you think your opponent would bet more than $80 before giving up, or you thought your opponent would put money in more frequently than the percents above then you might have a call here.
