Roulette Odds and Probability Explained

Understanding how roulette odds work is something that everyone who places a bet can benefit from. Using the odds, players can work out their chance of success with a particular selection, as well as how much money they might win if their prediction is right. Betting odds can look confusing, and especially when it comes to roulette, they can seem very inconsistent. This is because there are three main variants of the game, as well as numerous lesser-known versions. 

Probability in roulette refers to how likely it is that a bet will be successful. The higher the probability rate, the more likely it is that the player will score a win from that particular bet. Lower rates of probability mean that players are not as likely to be successful. In roulette, these less likely bets tend to come with a bigger payout, however. Probability rates can be shown as two numbers – for instance, in the case of a coin toss, where the odds are 50/50, it would be shown as 1/1 or 1:1. Shown as a percentage, it would mean that players have a 50% chance of winning. 

What are Odds in Roulette?

In any betting situation, the odds of winning in a game will depend on the range of outcomes that are covered by the wager. In European roulette and French roulette, for example, the player is facing one in 37 odds, as there are 37 pockets. As an American roulette wheel has 38 pockets, the player faces one in 38 odds instead. Nevertheless, in both cases, the player will get a payout for a straight bet of 35:1. For a bet that’s considered outside – one that covers 18 numbers, for example – the chance of winning is 18 in 37, or nearly 50%. Outside bets are ones that cover large expanses of the table, such as red and black or odd and even. 

To work out the odds of an individual bet, it’s necessary to consider the numbers that are covered by it, as well as the outcomes. The house edge, or advantage, is included with every betting option. It’s the mathematical advantage that the casino already factors into each game. It’s worked out based on the payouts of each bet, and in roulette, whether or not there is an additional zero pocket.  

Although it’s difficult to establish a winning strategy in roulette because it is essentially a game of chance, players can select the types of wager they want to place. They can choose several options that cover different areas of the roulette table, as this allows them to work with a set level of risk each time the wheel spins. Of course, a single straight bet, one in which a player goes for one number, is going to create the biggest element of risk, because it’s so difficult to land. However, sometimes players do go for those bets as part of a wider strategy, because when they do happen, they offer the biggest rewards. 


These odds are known as long odds, and they are used to refer to any outcome that the house considers unlikely to happen. This additional risk is shouldered by the player, of course, but it’s also the very thing that makes longer odds more profitable. For players who stick with long odds, they need to win big when a bet does land because these successes are so unlikely. For example, straight bets on the table come with odds of 35:1, so one bet in every 35 has to land for a player to break even, never mind walking away from the table with a profit.

This is why many regular players include plenty of research into their roulette strategy. If the idea is to make a profit and stay at the table for longer, it’s important to know exactly what is being wagered on and why that particular bet is being chosen. That is to say, what part does it play in the overarching strategy that a player is using? By remaining mindful of this, a player is more likely to experience success.

Playing style and personal preference can also be taken into consideration. Sometimes, a player will choose to chase longer odds in the hope of winning big. Other times, when players are looking to bag those even-money payouts more often, they will go for shorter odds and cover 50% of the table, hoping to get more frequent, smaller wins. 

In any type of variant, the roulette bet types can be arranged into two distinct categories based on the odds of winning. These are inside bets and outside bets. They are named depending on where they are placed on the roulette table. As the name suggests, inside bets are placed on the inside of the table. They include all the numbers that can be wagered on as groups, or their location on the grid or randomly. These are where all the long bets are placed. 

Roulette odds that are outside are found on the outer portion of the table. These bets cover a far wider range of eventualities, and as such provide a better roulette odds payout. It’s in this section that bets can encompass a dozen numbers, a column, high or low, odd or even, and red or black. The odds of winning with one of these bets is around 48% in French and European roulette and 47% in American roulette, but they all pay out at 1:1.

Understanding Roulette Payout

The one thing that remains consistent when it comes to roulette odds and payouts is the house advantage. Aside from this, the roulette odds payout system is based on 36 numbers. Therefore, to establish the payout, this number is divided by how many pockets a bet covers and then subtracted by one. So, by betting four straight wagers, the payout will be 8:1. For a more comprehensive view of all the odds and the wide range of payouts in each version of roulette, take a look at this table. 


Roulette bet type
Example roulette betPotential payoutEuropean roulette oddsAmerican roulette odds
ColumnAny number in the third column2:132.40%31.6%
DozenAny of 13 to 242:132.40%31.6%
Even betsBlack over red1:148.60%47.4%
Single number735:12.70%2.60%
Two numbersEither 19 or 2017:15.4%5.3%
Three numbersAny of 28, 29 or 3011:18.1%7.9%
Four numbersAny of 5, 6, 8 or 98:110.8%10.5%
Five numbersAny of 0, 00, 1, 2 or 36:113.5%13.2%
Six numbersAny of 4 to 95:116.2%15.8%

In every round, players can select multiple bets. These can include both inside and outside bets. On the inside, a basic straight bet will pay out at 35:1. Players can also go for a split, which includes two numbers that are adjacent either horizontally or vertically – for instance, eight and nine. These have a payout of 17:1. For consecutive number bets – of five, six and seven, for example – the payout for a win is 11:1. Another inside bet is the square. This includes a four-number spread set in the corner of a table – it could be 17, 18, 20 and 21, for instance. These bets come with a payout of 8:1.

On the outside, bets can be seen as more straightforward. The even or odd split does not include the zero pockets, as they count as neither. The payout for this bet is 1:1, or even money. Zero is also excluded from a red or black bet, but there are 18 black and the same number of red pockets, so it’s another even-money payout. The same is true of the low or high bet. This splits the table between 1 to 18 and 19 to 36 and offers 1:1 payouts.

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How to Maximize Roulette Odds?

Roulette is based entirely on chance. Once the ball starts spinning in the wheel, there is no way for either the house or the player to predict exactly where it will land. This means that there is no failsafe technique to boost the roulette odds. Instead, when it comes to getting the advantage during a session, the key is to know how the odds work and understand what they mean. 


Knowing what the different odds are can be useful when choosing the ideal bets and managing a bankroll. Players who are going to concentrate on inside bets will usually need a larger budget, as there is a lower chance of winning. They will need to bet through more rounds before they can expect to get a payout. Outside bets are different because they tend to result in small, consistent wins. Therefore, players may want to stake more of their bankroll on single bets.

Of course, there are also some very well-known strategies that players have been using for years to try to improve their results. One of the most popular is the Martingale strategy, but the Fibonacci and Paroli systems are also commonly used. They do take a while to master, but many people find that working with a set strategy enhances their play. 

Players who like to explore several variants will find that the roulette odds payout for the French and European games are more generous. They give the player more of an advantage, compared to the American version. 

Variations in Roulette Odds

There are many different variants of roulette. They all have unique rules and payouts, and some even have individual table layouts. These distinctive styles of play mean that each type of roulette has varying odds, both when it comes to the probability of profiting in general and the chances of an individual bet being a winner. Most major online casinos tend to stick with three main variants, European, French, and American roulette. 

There are 37 slots on a European roulette wheel and the ball can land in any one of them. Along with a zero, the other numbers run from one to 36. In most casinos, the house edge for this version of the game is around 2.70%. However, due to the La Partage rule, the house returns half of the value of a bet if the ball falls into zero after a player has placed an even-money bet. This reduces the house edge even further to 1.3%. Even without this rule, the even-money bets, which are some of the most popular for people playing this variant, have odds of 1:1 and a 48.65% probability. This means that the odds that are available in European roulette are some of the best around. 


In American roulette, there are two slots for zero. One is marked with 0 and the other with 00. It might not seem like a hugely significant change, but in fact this increases the house edge by a sizable 5.25%. This makes American roulette one of the least favorable in terms of its odds. There is a 47.40% chance of hitting a red or black bet on this table, though the odds remain 1:1. Furthermore, one of the best-known wagers in this variant is the five-number bet. This involves the player covering 00, zero, one, two and three, and comes with an even higher house edge of 7.90%. Also, this bet only pays out at six to one. 

Sharing a table layout with the European variant, French roulette has the same odds. The rules can be slightly more complex, but not in a way that impacts the probability for players. For a straight bet on a single number and various other individual bets, the win rate is 48.6% and the payout is 1:1. For more complex bets, there are potential winnings of 36 to one on offer, but less favorable odds. La Partage only applies to some versions of French roulette, mostly live dealer games. With a house edge of 2.70%, the payout on a standard French roulette table is the same as it is on a European table. 

Author: Tanya Fields

Campaign Acquisition Manager Length with RC: 1 year, 9 months Favorite Casino Game: Starburst Background in iGaming: Opened the iGaming Department at Hard Rock Atlantic City in 2018 in both Customer Service, and then CRM, prior to moving over to RC in January 2021 Location: Based in NJ at the RC HQ Content: Occasionally, but only as it pertains to RC