I know you didn´t ask for what i´m going to say, but perhaps it can help you. It´s the rule of 4 and 2: If you´re playing hold em, this rule could help you to know your
odds (approximately) after the flop and after the turn. It´s very simple, after the flop you have to count the outs you have and multiply them by 4. And after the turn is the same, but instead of multiplying your outs by 4, you multiply them by 2.
For example, if you have an open ended straight draw after the flop, you have 8 outs to hit your straight. So you multiply 8 x 4 = 32. You will hit the straight 32% (31.46% exactly) of the time. Then, if you don´t hit it in the turn, you can hit it 16% of the time in the river.