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Casino Games Odds Explained

Every game in a casino whether it is at a land-based or online casino will have certain rules. Just as each game has its rules, each game will have different odds and a house edge. The casino needs to take a portion of your bet to keep the business running. However, this doesn’t mean that the odds are always stacked against you.

Learning more about the odds of each game and what the casino stands to gain, will help you be more prepared for what you can expect from different games. With some games, you could even adjust the house edge, depending on how you play the game. It can get complicated but is also not too difficult to understand. Our team of gambling experts here at CasinoTop will guide you through the odds with ease.

How do Game odds Work at Casinos?

All gaming activities that take place at the casino revolve around different odds. When it comes to betting on events, here is what the odds tell bettors or players:

  • How much the bettor stands to win if their prediction comes true
  • How likely it is that an event will occur during a game or match

When looking at the probability of an event happening during a sports event, it will be displayed in one of the ways shown below.

Fractional Odds

The odds are presented as a fraction, as the name states. You will see numerators and denominators or numbers to the left of the slash and numbers to the right of it. The easiest way to explain it is that if you have odds of 10/1, betting the amount of the second number will win you the amount seen in the first number. So, if you place a bet of $1 then you stand to win $10.

If you see that the odds displayed for an event is 5/2 and you bet $4, you will still win $10 but will also see your initial stake returned. A good example would be ((Your Bet/denominator) x numerator) + bet. Which would appear as (($4/2) x 5) + $4 = $14

Percentage Odds

Use the following formula to turn your fractional odds into a probability percentage:
Probability Percentage = B / (A+B)

Using the odds of 10/1, A is represented by the 10 and B is represented by 1. That would give you a probability of 9%. The total will be represented in a decimal number, but multiply that by 100 to find the probability percentage.

At times you may also see the odds presented to you in decimal form. You know the calculation and will know how to convert it into a percentage to get a better understanding. You also need to remember that the odds for different casino games will not all be the same.

The Odds for Texas Hold ‘em

Graphics shown at a poker game broadcasted on TV will show a player's chances of winning a hand based on what they have in their hands and what's on the table. The number of cards left in the deck that will help you enhance your hand (also known as "outs") determines this percentage.

If, say, you are holding Q♠ and 9♠ and on the board is J♠ 2♠ 7♦ A♦, you would calculate your chance of winning the hand by:

Taking the number of cards in any suit (13), then subtracting the number of spades on the table and in your hand (4):

♠13 – ♠4 = ♠9

You now have nine outs. Here is what you need to do to calculate your estimated odds of seeing your flush through by doing the following:

Of that 46, there are 9 cards remaining that could complete your flush and give you a win. Thirty-seven cards remain that will cause you to lose if any of them are the last card to come out. This makes your odds of getting the win 37:9, which simplified down is around 4:1 (or 20%).

Quickly Calculating Odds in Poker

  • Do a calculation to determine the number of outs that are left in the deck after the flop occurs.
  • Take that number and multiply it by 4. This will then let you know your chance of getting a winning card on the river or turn.
  • Take the number of outs and multiply by 2, after the turn. This gives you information on the chance you have of winning with the river.

The Odds for Roulette

Things get interesting when it comes to roulette as the game has two versions each packed with its own set of odds. When looking at the American variant, nearly all the bets you place have a house edge of 5.25%. However, when you look at European roulette the house edge is lower, sitting at 2.70%. The percentage for the house edge is determined by dividing the number of zeros on the roulette table by the number of slots found in the roulette wheel.

House Edge


House Edge


Other odds for different variants can be calculated in the same way. If you bet on odd/even or red/black then the odds will be 18/38 = 47.37% on an American roulette table and 48.6% on a European Roulette wheel.

There are lower odds with roulette that you will see if you bet on a single number. This also happens when players do not bet on 1-18 and 19-36, even, odd, black and red.

Payouts, Bets and Roulette Odds

Single number35:12.63%35:12.7%
2 number combo17:15.26%17:15.4%
3 number combo11:17.89%11:18.1%
4 number combo8:110.53%8:110.8%
6 number combo5:115.79%5:116.2%
Combo of6:113.16%n/an/a

The Odds for Blackjack

You will have to learn about blackjack strategy if you want to get the best odds. This is the game where the best odds are, if you know what you are doing. Here is what the odds look like on a multi-horse shoe:

As you might expect, your chances of winning diminish as the value of your hand rises. Keep in mind that there are numerous variations and rule sets for blackjack, and the odds and strategy will all differ significantly.

The Odds for Craps

There are many betting combinations in the game of craps and many people find it difficult to understand the game’s odds. Find out more about what the odds are based on what you roll and the combinations of numbers.

Craps odds and combinations

Dice Total Possible Combinations Odds Odds %
31-2 2-117:15.56%
41-3 3-1 2-211:18.83%
51-4 4-1 3-2 2-38:111.11%
61-5 5-1 4-2 2-4 3-331:513.89%
71-6 6-1 2-5 5-2 3-4 4-35:116.67%
82-6 6-2 3-5 5-3 4-431:513.89%
93-6 6-3 4-5 5-48:111.11%
10 4-6 6-4 5-511:18.83%
115-6 6-517:15.56%

The more you play craps, you are likely to find that you or someone you know is on a winning streak. One of the longest winning streaks in history was recorded from an anonymous gambler at the Las Vegas Desert back in 1950. Reports stated that the player was able to manage a winning streak of 27. The odds that come with that kind of luck were calculated at 12,467,890 to 1. The player was doing things smartly and placing small bets to keep the winning streak going. Here is a chart that will help you play craps and also show you the difference between the best and worst craps bets players can choose to commit to.

The Worst and Best Bets in Craps

Bet True Odds Odds Paid House Edge
Pass Odds / Come OddsSame as paid2:1 on 4,10;3:2 on 5,9;6:5 on 6,80%
Don’t Pass Odds / Dont Come OddsSame as paid1:2 against 4,10;2:3 against 5,9;5:6 against 6,80%
Don’t Pass / Don’t Come (Bar-12 or Bar-2)976:9491:11.36%
Pass / Come251:2441:11.41%
Place 6 / Place 86:57:61.52%
Horn(the combined bet)5:127:4 on 2,12;3:1 on 3,1112.5%
Whirl/World(the combined bet)2:126:5 on 2,12;11:5 on 3,11;0:1 (push) on 713.33%
Any 75:14:116.67%

The Odds for Slots


Whether you play at a slot machine or your favourite online slot, the results from these games are determined by software called a random number generator (RNG) whenever you spin the reels. There are still many people that believe you can time slot games to find the perfect opportunity to win. There are no patterns or payout cycles when it comes to slots. There are always a large number of slots at any casino you attend and these games usually have the highest house edge of any game in the casino.

The average house edge for slots comes in at around 7%. However, the house edge for these games can change based on which jurisdiction you are in. Legally, casinos in Las Vegas have the right to offer RTP percentages of as low as 73% which means that the house edge comes in at 27%. Compare that to online casinos that usually have RTP percentages between 93-97% on average.

The higher house edge does make it more difficult for players to walk away with big wins as often as they would like. That doesn’t mean that there haven’t been huge winners in the past. However, it does mean that the odds are significantly stacked against players. The largest prize collected from slots came in at $39,710,826.36 with odds of 16 million to 1.

Calculating the House Edge

With online casinos, it is easy to find out what the RTP for an online slot is. It will be displayed on the rules section or the paytable menu. The figure will be presented as a percentage such as 95%.

It’s simple, all you need to do is take 100 and subtract the RTP and what’s left will be the house edge. Example: 100 – 95 = 5% house edge.

  • Each time you play your potential return will be in the range of nothing to the maximum prize amount.
  • The results are always random, so you always have a chance of winning or losing.
  • Each game will have a specific RTP

Reminder: Casinos always have an edge

You will only start to make a profit when playing casino games when you have a better understanding of how the odds work with different casino games. Be aware of your limits and realise that you may need to walk away if the odds are not in your favour. Even after consistently winning, you may need to stop and take a break.

Just like any business, casinos need to make a profit and it is for that reason that the establishment will always have the edge. Overall the odds will always be in the casino’s favour. With games where the odds and the house edge can change, take some time to enjoy free casino games and practice strategies to help you build your confidence without taking any risks.