How to calculate odds?

[Santo2True]

i don't know if anyone else does it this way, and it may have already been posted but i didn't read through the whole thread. but here is how i do my math:

1.How many “Outs” we have – Cards that will make us a winning hand
2.What are our “Pot Odds” – How much money will we win in return for our bet

To figure out my outs i use:
RULE OF 4 AND 2
Number of Cards still to come % probability we will hit our Outs
After the Flop – 2 cards to come (Turn + River) Number of Outs times 4
After the Turn – 1 card to come (River) Number of Outs times 2

outs/4x/exaxt%............................outs/2x/exact%

1 4 % 4.5 %...............................1 2 % 2.3 %
2 8 % 8.8 %...............................2 4 % 4.5 %
3 12 % 13.0 %..............................3 6 % 6.8 %
4 16 % 17.2 %..............................4 8 % 9.1 %
5 20 % 21.2 %..............................5 10 % 11.4 %
6 24 % 25.2 %..............................6 12 % 13.6 %
7 28 % 29.0 %..............................7 14 % 15.9 %
8 32 % 32.7 %..............................8 16 % 18.2 %
9 36 % 36.4 %..............................9 18 % 20.5 %
10 40 % 39.9 %.............................10 20 % 22.7 %
11 44 % 43.3 %............................ 11 22 % 25.0 %
12 48 % 46.7 %.............................12 24 % 27.3 %
13 52 % 49.9 %.............................13 26 % 29.5 %
14 56 % 53.0 %.............................14 28 % 31.8 %
15 60 % 56.1 %.............................15 30 % 34.1 %
16 64 % 59.0 %.............................16 32 % 36.4 %
17 68 % 61.8 %.............................17 34 % 38.6 %

so once we caculate our outs and come up with %chance of hitting that out on which street we need to figure out our pot odds.

Break Even Percentage = 100% divided by (Pot odds added together)

Pot Odds added together means replace the “to” with a plus sign. in example: 3 to 1 becomes 3+1 = 4

so for example, we hold KTo and there is OESD on the flop as it comes
QJ6r

Open Ended Straight Draw = 8 Outs (4 Aces and 4 Nines)
King Top Pair = 3 Outs (4 Kings less the King in our hand)

Total Outs = 11 Probability of Winning = 11 x 4 = 44%

Lets say the pot on the flop =$40

Total Pot is now $40 and we are asked to call $10 so our Pot odds are 4 to 1 and our break even % = 100% divided by 5 = 20%.

which gives us (44% vs 20%) so in this example it will be a "correct" call and in the long run a "profitable" call

That's just the simple math I use and it might look crazy at first, but the more you use it the easier it gets and soon you will keep all the numbers in your head and be able to do them on the fly. GL

[Sasquach991]

...
so for example, we hold KTo and there is OESD on the flop as it comes
QJ6r

Open Ended Straight Draw = 8 Outs (4 Aces and 4 Nines)
King Top Pair = 3 Outs (4 Kings less the King in our hand)

Total Outs = 11 Probability of Winning = 11 x 4 = 44%

Lets say the pot on the flop =$40

Total Pot is now $40 and we are asked to call $10 so our Pot odds are 4 to 1 and our break even % = 100% divided by 5 = 20%.

which gives us (44% vs 20%) so in this example it will be a "correct" call and in the long run a "profitable" call

That's just the simple math I use and it might look crazy at first, but the more you use it the easier it gets and soon you will keep all the numbers in your head and be able to do them on the fly. GL

The 4x rule is used for a shove or limit (I think) because in no limit there will usually be another bet on the turn and you have to reevaluate again.

For the turn or river just use 2x+1. And don't for get about implied odds.

[texa8]

Total Pot is now $40 and we are asked to call $10 so our Pot odds are 4 to 1 and our break even % = 100% divided by 5 = 20%.

which gives us (44% vs 20%) so in this example it will be a "correct" call and in the long run a "profitable" call

mmm this is true for a shove yes but really we should be looking at making our hand on the next street, i.e. 11 x 2 = 22% chance of making our hand.

This is also a very optimistic scenario and villian will often bet at least 1/2 psb, something like $25 into $40 meaning we are calling $25 to win $65 and are 2.6 to 1 and need %27 and a fold is nearly always correct...

until of course we factor in our implied odds. in this case if we feel we can extract another $20 on the turn we are calling $25 to win $85 and we are effectively 3.4:1 or about 22%.