-52 cards in a deck
-you receive 2 and see 3 on the flop. 52-5 = 47
-If you're drawing to an Ace (3 outs) your odds are 3/47. Which is means 3 cards in a deck of 47 remaining will help you. Or 44 cards in a deck of 47 remaining do not help you.
-The same is for the turn, except it'll be 3/46 cards.
Originally Posted by Rounder_D
the easiest way is take your outs and multiply by 4 on the flop thats simple math by rounding it up. for example 9 x 4 36% not exact but close enough
This is only if you're going to see 2 cards (turn and river) without any more betting in between-like if there is an all in on the flop. However, if there is a chance of more betting on the turn, you do not figure for 2 cards to come, but 1 card. So, if you have 9 outs, 9x2= ~18% chance of hitting on the turn. Then you figure again for the river if you dont hit 9x2 = ~18% chance.
Also, this is dealing with hand odds, not pot odds