Start with the wheel you are sitting at
The count of odd slots changes the moment you switch between the two main wheel layouts. A European roulette wheel carries 37 pockets numbered 0 through 36, while an American wheel carries 38 pockets with an added double zero. The odd-numbered pockets are the same on both: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33 and 35. That is 18 odd numbers. The difference between the wheels comes from the zero pockets, which are neither odd nor even.
So the direct answer is 18 odd slots on either wheel. What changes is the proportion of the wheel those 18 pockets represent, and that is where the house edge on an odd/even bet shifts.
Why the zeros matter more than the count
An even-money bet on odd pays 1 to 1. If the wheel contained only the 36 numbered pockets, the bet would be a coin flip: 18 odd pockets against 18 even pockets. The zero pockets break that symmetry. On a European wheel, the ball can land in 37 pockets, and only 18 of them pay your odd bet. The single zero is the house's pocket on every even-money wager. On an American wheel, the double zero adds a second pocket that also loses, which is why the same odd bet carries a larger built-in disadvantage on that layout.
This is the mechanism behind the rule that the extra pocket increases the house edge on the American layout. The zero does not secretly count as odd or even; it simply sits outside the bet and loses it.
| Wheel type | Total pockets | Odd pockets | Even pockets | Zero pockets | Odd bet loses on |
|---|---|---|---|---|---|
| European | 37 | 18 | 18 | 1 | 19 pockets |
| American | 38 | 18 | 18 | 2 | 20 pockets |
The table shows why the American layout is the poorer choice for an even-money bettor: the same 18 winning pockets now sit against 20 losing pockets instead of 19.
Reading the sequence of a round
Knowing the count is one thing; using it at the table is another. A round moves through a fixed sequence, and the odd/even bet is only one decision inside it.
You buy in at the table with cash or a casino credit instrument, and the dealer exchanges that for wheel-specific chips. Those chips carry no printed denomination and only work at that table, so you cash them back before you leave. You place your odd bet on the marked outside section of the layout before the dealer calls no more bets. The ball is spun, settles in a pocket, and the dealer marks the winning number. Losing outside bets are cleared first, then winning outside bets are paid at 1 to 1.
The procedural mistakes new players make cluster around that sequence. The most common is touching or adding chips after the dealer has announced that bets are closed. Another is assuming the zero pockets count as odd or even, which they do not on any standard layout. A third is placing an outside bet with table-minimum chips after buying in with inside-denomination chips, which the dealer will need to correct before the spin.
How the odd bet compares with other outside bets
Odd sits in a family of even-money outside bets: red or black, high or low, and even. All four cover 18 numbered pockets and lose on the zero pockets. The difference between them is cosmetic in terms of edge, because they all face the same losing pockets on a given wheel. What differs is the player's reason for choosing one: some players track colour, some track high/low ranges, and some prefer odd because it splits the wheel into alternating numbers rather than contiguous sections of the layout.
Inside bets work differently. A straight-up bet on a single number covers one pocket and pays at a higher multiple, but it loses on 36 or 37 other pockets depending on the wheel. The trade-off is between how often a bet pays and how much it pays when it does, which is volatility, not a change in the underlying return of the game.
| Bet | Pockets covered | Losing pockets on European wheel | Payout style | What the player is choosing |
|---|---|---|---|---|
| Odd | 18 | 19 | 1 to 1 | Frequent small wins |
| Even | 18 | 19 | 1 to 1 | Frequent small wins |
| Red or black | 18 | 19 | 1 to 1 | Frequent small wins |
| High or low | 18 | 19 | 1 to 1 | Frequent small wins |
| Straight-up number | 1 | 36 | Higher multiple | Rare large wins |
The table keeps the comparison honest: the outside bets are structurally identical in coverage and payout, while the inside bet trades frequency for size. None of them removes the zero pocket from the wheel.
Where the printed rules state the numbers
If you want the exact figures for the table in front of you, the wheel itself is the primary document. Count the zero pockets: one means the European layout, two means the American layout. The table's minimum and maximum outside-bet limits are printed on a placard at the table, and those limits apply to the odd bet just as they do to red, black, high and low. The payout for an odd bet is printed on the layout as a fixed multiple of the stake.
For online play, the game's information panel or rules screen states the wheel type, the number of pockets, and the payout schedule. Read that panel before the first spin rather than after a losing zero, because the zero is the one outcome that behaves differently from what the word "odd" suggests.
FAQ
Is the zero an odd number in roulette?
No. On both European and American wheels, the zero and double zero pockets are neither odd nor even. They sit outside the odd/even split and cause every odd or even bet to lose when the ball lands on them.
Does an odd bet pay differently on an American wheel?
The payout is the same 1 to 1 on both wheel types. What changes is the number of losing pockets: the American wheel adds a second zero, so the same odd bet loses on 20 pockets instead of 19.
Are there roulette wheels with more than 18 odd numbers?
Not on a standard wheel. The numbered pockets always run 0 to 36, so the odd pockets are always the same 18 numbers. Any wheel with a different count of odd numbers would be a non-standard or novelty layout, and its rules would need to be read separately.
If you or someone you know is struggling with gambling, help is available. Contact the National Gambling Helpline for free, confidential support, available 24/7, every day of the year. You are not alone.
Play responsibly
Gambling should be treated as paid entertainment, never as a way to earn income or recover losses. 1-800-MY-RESET (1-800-697-3738)
18+ or 21+ depending on where you are; follow the minimum age that applies to you.
This article is general information about how these mechanics work. It is not legal advice and not a recommendation to gamble or to use any particular operator. Availability and legality differ by jurisdiction — check the rules that apply where you are.