Originally Posted by ClubKid
It's always the same. Whether they bet less or more than the pot, you are calculating your percentage of the TOTAL pot.
So if the pot is $50, and they bet $100, you have to call $100 into a pot that will be $250 (including your call). So your pot odds as a percentage are 40%.
In fact, no matter how much they over bet, you will never have pot odds over 50% (or 1 to 1). Consider this example - you are playing in a game with no blinds, no antes, head's up. Your opponent goes all in for $1,000. Your $1,000 is exactly 50% of the total, $2,000 pot.
Since there are always some blinds/antes (i.e., an existing pot in the middle), you will always be less than 50%. This is because your money is always matched at least evenly in poker.
I remember you asked some questions before, though.
To be honest, do not hang yourself up too much on the math. Most decisions are automatic, you just have to learn to recognize what hand fits what scenario. If someone bets the pot, you're never going to have odds to call with pretty much any draw in holdem, unless you have a 21 outer (open ended straight flush draw plus two live overcards). This is why normally, with big draws like an open end straight flush draw, it probably makes more sense to just move all in (on the flop), because you'd rather see TWO cards, even though it means risking your whole stack on the draw. With lesser draws, the same applies, except your bluff equity also starts to factor in (i.e., does raising opponent all in also potentially get him to fold the better hand enough times that it makes the play a winner over many trials).
The only time you really need to calculate at the table is if you play limit poker, or if you have odd scenarios in NL holdem (like if you're on the turn, but many opponents in, and someone bets half the pot - if enough people call, you might still have pot odds to chase a open end straight draw; or if you're on the flop, and someone bets very small, like 1/3 pot or less).
I hope this helps. It would be more useful (I think) if you post any hands you have trouble with specifically. That is better too because you will remember the decision making process you made in reviewing the hand, and you will be able to make the (correct) decision very quickly whenever it comes up again!
Let me give you an example. When I first started playing, in limit holdem, I wasn't so sure calling the flop with just two overcards was a good idea. I'd find myself calculating too much, and not thinking about other things, like, who is in the hand, am I drawing live most of the time against them, what is the board texture, etc. So I simply reviewed some hands after they were played, and memorized how may bets had to be in the pot at a MINIMUM to make calling with two overcards (a six outer) the right play. So now I just think of it in terms of, was it raised with three players in plus the blinds - if so (7.5 small bets), and one person bets, and I am not afraid of a raise (due to my position or reads), I know I have odds to call with overcards (or with a better draw, of course).