Understanding and Calculating Pot Odds in Poker

As someone who plays poker several hours a week, I am constantly amazed at the number of players I run into who don’t understand exactly what pot odds are. Calculating pot odds is absolutely essential to maximizing the profit of each hand you play. As such, I’ve decided to write this article explaining how to calculate pot odds for those who have yet to figure out why it's so important.

Most people are familiar with the term odds. For those of you who aren’t, odds are the statistical probability that something will or will not happen. Odds are typically verbalized by saying “5 to 1”, or “3 to 1”, and are expressed in the following notational format: 5:1, 3:1, etc. If there’s a 10 percent chance of rain, it means there’s a 90 percent chance of it NOT raining. Thus, the probability of it raining would be 90:10, or 9 to 1 against.

Still Confused? Let’s look at another example:

Let’s say you roll a single die. There are six possible outcomes: the numbers 1 through 6. What would the odds be of rolling any single number on that die? Well, you have a 1 in 6 chance of rolling any particular number. Five of those numbers lose for you, while 1 does not, so the odds of rolling any particular number are 5 to 1 against.

Ok, I understand what odds are. What the heck are pot odds, and how do I calculate them?

Simply put, pot odds is the ratio between the money already in the pot and the money you will need put into the pot to keep playing. For example, let’s say there are 300 chips in the pot. Your opponent, who is first to act, bets 100 chips. There are now 400 chips in the pot (300 original + the 100 chip bet). In order to keep playing, you must match the bet made by your opponent of 100 chips. This means the pot odds are 400 (money in the pot) to 100 (what you need to call). Broken down more simply, 400:100 can be factored down to 4:1, or 4 to 1 pot odds.

That’s all great, but why exactly should I care what my pot odds are?

You should care because poker isn’t just a game of skill; it’s also a game of probability. In order to maximize your long term profit, you will need to understand the basic concepts of probability and its place in poker. Without a proper understanding of how it applies to your game, you could find yourself folding and calling at the mathematically incorrect times.

Ok, losing money is a good enough reason. Show me how calculating pot odds can improve my game.

First off, knowing how to calculate pot odds doesn’t do you much good by all by itself. However, when you compare your pot odds with the odds of winning a particular hand, you have a very powerful tool at your disposal. Let’s take a look at a “non-poker” related example…

Let’s say someone approached you with an offer. They were going to flip a coin 100 times. Every time heads hit, they had to pay you two dollars. Every time tails hit, you had to pay them 1 dollar. Who is getting the better end of the deal? Certainly you are because you are getting 2 units of money for every one that you are risking (2:1 money odds), on a gamble that is 50:50, or 1:1.

Many poker situations are no different. Let’s say you’re on the button with A4 of spades. One player has already limped in front of you. You elect to limp in behind them. The small blind folds, and the big blind checks. The pot is 175 chips going heading to the flop. The flop comes K of diamonds, 8 of spades, 5 of spades. The big blind (who was short stacked) bets out his last 100 chips, and the early limper decides to fold. Now, you’re fairly certain that the big blind has a king with a small kicker, or possibly an eight, which means you’re currently behind in the hand to his pair. How do you know whether or not it’s mathematically correct to call?

The first thing to figure out here is what your pot odds are. There were 175 chips in the pot before your opponent bet. He then added his remaining 100 chips. For you to call and see the remaining two cards, you must call his 100 chips. Thus, the pot odds are 275:100, or 2.75 to 1. The next thing to figure out is what your odds of winning are. Assuming he does indeed have a pair, any ace will win the hand for you, as would any spade. There are 3 aces left in the deck, and 9 spades. Your 12 outs give you roughly a 45% chance of winning with two cards to come. Thus, your odds of winning are 55:45, or 1.22:1. Over the long run, calling this bet will be profitable because when you win (45% of the time), you will win 275 chips. Conversely, when you lose (55% of the time) you will lose only 100 chips. Your primary goal is to have better pot odds than winning odds. As long as you keep taking gambles that are in your favor from a pot odds perspective, you will come out ahead mathematically.

Any solid player will tell you that knowing how to calculate pot odds is an essential part of any poker player’s toolbox. By understanding how it applies to your poker strategy, you will increase your overall profitability by folding or chasing in the right spots.