How to Calculate Outs in Texas Holdem Poker

An ‘Out’ in poker refers to a card that could appear on the turn or river that will improve your hand, for example a card that would make you a flush or a straight. Understanding outs is a key skill in Holdem as it will allow you to make ‘good’ decisions based on your chances of improving to the best hand and the odds being offered. This article looks at how to effectively calculate outs in different situations and use this information to your advantage at the tables.

We will start by looking at how to work out the number of outs you have in some common situations, covering the importance of not double-counting certain cards. Next the chances of improving based on outs as a proportion of unseen cards will be covered. Finally, a simple rule of thumb for calculating your chances of improving with one or two cards still to come is introduced.
The most common situation in which you will need to calculate outs is when you have a flush or straight draw on the flop. For example where you hold two hearts and two more appear on the flop, here any additional heart has a good probability of making you the best hand.

To work out your outs you need to know how many of the unseen cards left in the deck will help your hand. In the flush example there we 13 hearts to begin with and you have seen 4 of these (2 in your hand and 2 on the board), leaving 9 hearts in the deck. With an open ended straight draw, for example you hold J-10 on a board of 2-K-Q then any 9 or Ace is considered to be an out – in this case there are 4 of each among the unseen cards, giving you a total of 8 outs.

Beginning players often make the mistake of double counting outs when holding a combination of draws on the flop. Take the example where you hold J-10 of diamonds on a flop of 2 (diamonds)-Q (diamonds) – K (spades). This is an excellent situation where you have outs to both a straight and a flush. Any of the 9 remaining diamonds are outs in this situation – along with the 9’s and aces. However, you have already counted the 9 of diamonds and ace of diamonds in your flush outs. This means there are only 3 * 9’s and 3* aces as additional outs to your straight, giving you a total of 15 outs.
Calculating whether to call a bet based on your outs involves knowing how many cards improve your hand as a proportion of the unseen cards in the deck. After the flop in Holdem you will have seen a total of 5 cards of the initial 52, the 2 in your hand plus the 3 on the board. This leaves a total of 47 unseen cards after the flop and 46 after the turn. Working out your chances of improving involves dividing the number out outs by the total of unseen cards. In the straight + flush draw example you have 15 outs. 15/47 means you will improve almost one time in three.

There is a simple rule that experienced players use to calculate the number of outs with one and two cards to come. This is called the ‘rule of 4’ and simply multiplies the number of outs by 4 for two remaining cards. For example if you have 10 outs with 2 cards to come then your chance of improving is approximately 40%, with just one card to come you can halve this to 20%.
To summarize, an ‘out’ in Holdem a card in the as yet unseen deck that will improve your hand. The most common examples are cards that will make you a straight or a flush on the turn or river. Calculating your chances of actually improving involve dividing your total outs (being careful not to double count) by the total of unseen cards. The ‘rule of 4’ will give you an approximation of this chance which is good for most Holdem situations.