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Guide to Roulette odds and Probabilities

Last updated: 12.07.2023 by Chris Mwangi

Roulette is a game based on mathematical foundations and each type of bet has a different probability. This is one of the features that makes it one of the most popular casino games in the world: by choosing the right bets, you can actually increase your chances. In other words, your chances of winning depend on which bet you choose, so knowing about roulette odds is very important. In this guide, we will talk about the odds of different types of bets and show you how to calculate these odds.

How to Calculate Roulette Odds?

To find out what your chance of winning on a particular bet is, you need to divide the numbers covered by that bet by the total number on the roulette wheel and multiply the result by 100. As a result of this process, you can see the percentage of winning chance for that bet. For example:

  • European roulette has 37 numbers (0-36).
  • If you place a straight bet, you are betting on a single number. This can be formulated as 1/37.
  • The result of 1/37 is 0.0270.
  • For convenience, multiply this result by 100 and you'll see how likely it is to win a straight bet on European roulette.
  • 0.0270 x 100 = 2.7%

Let's give another example using the red/black bet. This bet includes a total of 18 numbers. So:

18/37x100 = 48.64%.

Note that these examples only apply to single zero roulette variants (European and French). American roulette has 38 numbers in total and the formula needs to be changed accordingly.

Odds = Number of occupied field Number of overall fields x 100%

Number of overall fields = 36 for single zero roulette

Number of overall fields = 37 for single double zero

Odds of Roulette Bets

In the table below, you can see the odds of classic roulette bets. We've listed what your chances are for all bet types, so you can understand how to use your budget effectively and see what to expect from each bet. As you can see, when it comes to winning odds, outside bets offer better percentages.

Bet Odds (single zero version) Odds (double zero version) How to calculate (single zero) How to calculate (double zero)
Straight up 2,70% 2,60% 1/37*100 1/38*100
Split 5,40% 5,30% 2/37*100 2/38*100
Street 8,10% 7,90% 3/37*100 3/38*100
Corner 10,80% 10,50% 4/37*100 4/38*100
Basket - 13.20% - -
Six Line 16,20% 15,80% 6/37*100 6/38*100
Column 32,40% 31,60% 12/37*100 12/38*100
Dozen 32,40% 31,60% 12/37*100 12/38*100
Even/Odd 48,60% 47,40% 18/37*100 18/38*100
Red/Black 48,60% 47,40% 18/37*100 18/38*100
High/Low 48,60% 47,40% 18/37*100 18/38*100

Odds of Announced Bets

The table below shows what the odds of announced bets are. As known, these bets are “Voisins du Zero”, “Orphelins”, “Tiers du Cilindre”, and “Jeu 0 Bets”. Compared to classic bets, each covers multiple numbers and therefore offers different odds. Some of them even cover more than 40% of the wheel.

Bet Odds How to calculate
Visions du zero 45.95% 17/37*100
Orphelins 21.62% 8/37*100
Tiers du cylindre 32.43% 12/37*100
Jeu 0 18.70% 7/37*100
Neighbours 13.8% 5/37*100

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Roulette Odds Calculator

And below, we offer the odds calculator developed by Roulette 77 for free. This tool will automatically calculate and display your chances of winning in different bet types, taking into account your stake, without using the above formula. It is a more practical way of seeing all roulette odds.


What bets in roulette have the highest odds?

If we just look at odds, outside bets always offer better percentages. This is because they cover more numbers. Outside bets that pay 1:1 have the highest odds in this regard, as they offer a winning chance of over 48% at European roulette.

What is the house edge in roulette and how it is calculated?

The house edge is the value that shows the profit the casino makes from the roulette bets. For example, if the house edge is 2.7%, this means that for every 100 GBP wagered by the player, the casino will earn 2.70 GBP. The “0” pocket on the roulette wheel belongs to the casino and this is taken into account when calculating the house edge. For example, European roulette has a single 0, so the house edge is 2.7% (1/37). In American roulette, there are two 0s (0-00), so the house edge is 5.26% (2/38).

What are the odds of 0?

Betting on the number 0 is still betting on a single number, so it's a straight bet. Like all other straight bets, the odds of 0 are 2.7% (1/37) on European roulette and 2.63% (1/38) on American roulette.

Do la partage and en prison increase odds?

These are betting rules and they do not increase or decrease odds. In roulette games where the rules of La Partage or En Prison apply, the odds are still the same: your chances of winning a bet do not change. However, these rules allow the player to get a partial refund on the lost wager or use it in the next game. This results in a lower house edge (as low as 1.35%).

What is RTP in roulette?

RTP is short for “return to player” and is the opposite of house edge: it shows how much of the wagered money the player can win back in the long run. For example, the RTP of European roulette is 97.30%. This means that for every 100 GBP wagered, 97.30 GBP can be recovered.

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