how do you determine your odds?

hey i was just wondering how does one determine their chances of winning in a hand?

i was playing a guy today that mentioned to me that i was a 3 to 1 favorite when i got him to fold his hand. So i thought what a great tool it would be to be able to make calculations on the fly. I'm fairly decent when it comes to quick thinking math skills, so can someone give me some kind of formula for making quick calculations?

thanks!

First off widow being a fav and odds to catch a hand r 2 totally different things ,(which sixsixtie is talkin about in his reply)second off all thats not a very good explanation that sixsixtie gave u on catching your hand its if u havent seen 47 cards which is the amount of cards in the deck u havent seen including your hole cards (based on the previous reply of nine outz )after the flop and your odds r basically around 1.9 to 1 which means u should be gettin 2 to 1 on your bet/ money invested in the pot so every dollar u bet u should make 2 dollars off of it, and from the turn to the river there r 46 unknown cards so u take the number of outz u have again and take that number divide it by the number of unseen or unknown cards which is 46 (divided by nine outz in the example from the previous reply which was nine again) that leaves u with the odds of about,4 to 1 so your bet should net u 4 dollars to every one dollar u bet , not trying to be corrective but sixsixtie u gotta be careful givin people info that is way wrong. P.S. widow when u divide those numbers wth a calculater , 9 goes into 46 like 5.11 times but u have to subtract one from that number which is how u end up with 4.11 to 1 , its the same for all your odds calculation for outs . hope i could help u out a lilttle.

Here's the deal on the flush draw:

You have 2 suited cards and 2 suited cards are on flop. Assume any card of that suit will give you a winner. So you have seen 5 cards from the deck. 47 remain, of which 9 are in your suit. So, 9 winners and 38 losers. That means you are are a 38:9 underdog to make your flush on the turn or you will make it 1 time for every 4.22 times you don't. That's why people approximate 4:1 in pot odds, but it's actually a bit worse than 4:1.