Understanding How Many Numbers Are On a Roulette Wheel
Roulette is one of the most recognisable casino games, known for its spinning wheel, bouncing ball, and colourful layout. It looks simple, but every pocket and number has a purpose.
This article explores how many numbers can be found on roulette wheels, what those numbers mean, and how their arrangement affects play.
Whether you are new to roulette, or exploring online versions at UK-licensed casinos like O’Reels, understanding how the wheel is built can help you make more informed choices.
What Does a Roulette Wheel Look Like?
A roulette wheel is a round disc that spins horizontally on a fixed base. Around the edge are narrow slots, or pockets, each marked with a number.
When the wheel spins, a small white ball is rolled in the opposite direction. When the ball slows and lands in one of the pockets, that number becomes the winning result.
Most roulette wheels used in UK casinos, including those at O’Reels, follow the European design. This wheel contains numbers from 0 to 36, creating 37 total pockets. The 0 pocket is green, while numbers 1–36 are evenly divided between 18 red and 18 black. Each of these numbers also appears on a separate betting table, where you can place chips on single numbers or groups such as red/black, odd/even, or high/low.
Roulette is a game of chance. Each spin is independent, and there is no guaranteed outcome or system that ensures a win.
How Many Numbers Are There on a Roulette Wheel?
A European roulette wheel has 37 pockets numbered 0 to 36. This is the standard format for most UK games. Because every pocket is equally likely, the chance of hitting any single number is 1 in 37, or about 2.70%.
In American roulette, there are 38 pockets. The extra 00 (double zero) increases the total possibilities to 38, lowering the probability of a single-number win to 1 in 38, or about 2.63%. This small change also raises the casino’s edge.
The European version is the one you will most often see in many UK-licensed casinos. However, some online games may offer alternative formats or themed versions, so it can be useful to check the game’s information panel to confirm which wheel is used.
European vs American Roulette: What’s the Difference in Numbers?
While both wheels feature numbers 1 to 36, their layouts differ because of the extra pocket on the American version.
- European roulette includes one green zero and numbers 1–36. The house edge is about 2.70%.
- American roulette adds a green double zero, taking the total to 38 pockets and increasing the house edge to around 5.26%.
This means that in the American version, the chance of winning on even-money bets—such as red/black or odd/even—is slightly lower. In European roulette, these bets cover 18 of the 37 pockets, giving a winning probability of 48.6%. In American roulette, they cover 18 of 38 pockets, or 47.4%.
Although the difference seems small, it affects long-term averages and how frequently certain outcomes may occur. European roulette remains the most common format in the UK and across most online platforms.
Why Does Roulette Have a Zero?
The zero pocket is central to roulette’s design. It gives the game its distinctive mathematical balance and defines the casino’s edge.
Zero is coloured green and sits outside the even-money categories such as red/black or odd/even. If the ball lands on zero, most bets on those categories lose. This is what prevents roulette from being an exact 50/50 game.
For example:
- A red bet covers 18 numbers out of 37 on a European wheel.
- This gives a 48.6% probability of winning and a 2.70% house edge.
Some variations, such as French roulette, include special rules for zero. The La Partage rule, for example, returns half of an even-money stake if the ball lands on zero. These features reduce the house edge, but aren’t found on every table, so it can be worth checking the rules before playing.
How Are the Numbers Arranged on the Wheel?
Roulette numbers are not arranged in numerical order. Instead, the sequence is set to create a balanced spread of high and low, odd and even, and red and black numbers around the wheel.
On the European wheel, red and black pockets generally alternate, though there are occasional same-colour adjacencies to maintain symmetry. The green zero sits apart at the top of the wheel. This layout ensures that no long runs of consecutive highs, lows, or odds appear next to one another.
This design also explains why certain bets—like neighbour bets or section bets—refer to groups of numbers based on their position on the wheel, rather than their numerical sequence. These bets are common in European roulette and can be seen in games such as Roulette Nouveau and European Roulette Platinum at O’Reels.
All licensed UK roulette games, both online and in physical venues, are tested to ensure that the spin and result are random and fair, meeting Gambling Commission standards.
Differences in Layout Between European and American Wheels
Although both versions contain similar numbers, their order around the wheel is entirely different.
- The European layout features one green zero and a fixed arrangement of alternating red and black numbers from 1 to 36. The wheel is designed to balance opposite sides evenly, distributing odd and even numbers throughout.
- The American layout includes two green pockets—0 and 00—positioned opposite each other. The remaining 36 numbers are arranged in a different sequence, which alters the distribution of highs, lows, and colours around the wheel.
This means certain combinations that sit next to each other on a European wheel may not be neighbours on an American one. The double zero pocket also slightly shifts betting sectors, changing how some section bets cover the board.
Because of these variations, it can be useful to read the game’s information section before betting to understand which version is in use and how the layout affects specific wagers.
Play Roulette Online at O’Reels Casino
O’Reels is an online casino licensed by the UK Gambling Commission (UKGC), which means it meets UK standards for player protection. You will find a wide choice of online casino games here, including several roulette options to suit different preferences.
Log in or join O’Reels to browse the game library and pick from classic styles or newer versions with unique features. Each game includes clear information about the rules and potential payouts, so you can read how it works before you bet. As with all casino games, roulette outcomes are determined by the spin and cannot be predicted.
Please play responsibly. Set limits that suit you, and take breaks when you need them. Understanding how many numbers are on the wheel, and how they are arranged, can help you make more informed choices if you play.
*All values (Bet Levels, Maximum Wins etc.) mentioned in relation to these games are subject to change at any time. Game features mentioned may not be available in some jurisdictions.
**The information provided in this blog is intended for educational purposes and should not be construed as betting advice or a guarantee of success. Always gamble responsibly.