A Guide to Roulette Odds
The game of roulette is based on math, and this means that calculating the actual chance for one outcome or another is always a viable way. While knowing the outcome will not actually help you necessarily win more (because it’s all pure chance, remember) you can at least understand what bets have an advantage. Today, we take a look at roulette odds, and how they are calculated and offer you a quick tool for you to quickly remind yourself about the odds of each bet without having to do the calculations manually. Let’s take a look at what we mean here.
How to Calculate Roulette Odds?
To understand roulette odds and calculate them, you need to be familiar with the formula. It’s simple. You take the numbers covered by your bet and divide them by the total roulette numbers (depending on your version of the game). Then you multiply by 100. That is how this works. Let’s take a look at a few examples to get a better understanding of the pattern, starting with European roulette, which has 37 numbers (0-36).
- You make a straight bet which means you need to divide 1 by 37
- The result of this is 0.0270, but this is not yet the actual chance
- You need to multiply by 100 for 2.70%
Now, you just found out that if you bet a straight bet on European roulette, you have a 2.70% chance of winning. Let’s take another example. Let’s say you bet on black & red. That’s 18 numbers, so what you do is divide 18 by 37 and multiply by 100 for a total of 48.64%.
Please do remember that these calculations only apply for European roulette – or any variant of the game that uses the same version of the game.
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
If you want to figure out the odds of the different roulette bets at a glance, all you need to do is to have a handy reference by your side. This is why we have collected all probabilities depending on the bet type and listed them in a table displaying the winnings odds and percentages for you to see.
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 |
5 numbers | - | 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 |
Announced Bets, What Are the Odds?
One of the most interesting types of bets is the so-called French or Announced Bets. They feature options such as Jeu 0 Bets, Orphelins, Voisins du Zero and Tiers du Cilindre. Because of how popular they are, we figured out that having a dedicated table with the winning percentages will actually make a lot of sense. This is why we invite you to reference the below table if you are looking to find out the probabilities of winning each one.
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 |
Learn about probabilities, then play online roulette

Roulette Odds Calculator
If you want to really get the hang of roulette odds and probabilities, we advise you to simply use the Roulette 77 calculator we have developed for you. The solution will allow you to enter any bet type and automate the formula, giving you the exact probability, you can expect from each bet depending on the version of the game.
FAQs
The highest odds in roulette are attributed to the Even Money bets, those that pay 1:1. They have a house edge of more than 48%, usually – at least in European roulette.
The odds for a 0 in European roulette are 2.70%. This is based on the single-zero layout. If you are betting on American roulette, then the chance is slightly worse, 2.63%.
Yes, the house edge is calculated based on the number of zeros you have. So, a single zero needs to be divided by 37 and multiplied by 100 to get the house edge – 2.70%. For European roulette, the house edge is 2/38*100 – 5.26%.
You will have a smaller house edge with La Partage and En Prison, but the chances of each bet (its odds) will remain intact.
This is the expected return the player can get when playing a game of roulette. It’s basically how much money you earn back on every $100 you bet.