Not to be confused with roulette table, the physical layout with betting areas.
Casino & Table Games
Roulette odds
Roulette odds describe the probability of winning a bet and the payout the casino offers for it, with the difference between the two creating the house edge.
Key points
- Roulette odds are not a single bet type; they describe the probability and payout for any roulette bet.1
- Even-money bets like red/black cover 18 pockets, so on an American wheel the chance of winning is 18/38 and losing is 20/38.3
- The expected value for a $1 standard bet is (36/n) − 1, where n is the number of pockets on the wheel.1
- Payouts are set below the true odds of winning; that gap is the house edge, also called the vig or vigorish.2
- The term 'odds' can refer to true odds (based on probability) or payout odds (what the casino pays), and the two are never equal in roulette.4
Odds comparison: European vs American roulette
| Feature | European | American |
|---|---|---|
| Total pockets | 37 | 38 |
| House edge | 2.70% | 5.26% |
| Straight-up chance | 1/37 | 1/38 |
| Straight-up payout | 35 to 1 | 35 to 1 |
How roulette odds work
- Count how many wheel pockets match your bet (e.g., 1 pocket for a straight-up, 18 for red/black).
- Divide that number by the total pockets (37 or 38) to get the probability of winning.
- Compare the payout (e.g., 35 to 1) to the true odds: the payout is always lower, creating the house edge.1
True odds vs payout odds
True odds reflect the actual probability of an event. For a straight-up bet on a European wheel, the true odds of winning are 1 in 37, or 36 to 1 against. The casino pays 35 to 1 instead. That one-unit difference is the house edge, which for European roulette is 2.70%. On an American wheel the true odds are 1 in 38, or 37 to 1 against, and the same 35-to-1 payout yields a 5.26% house edge.61
This pattern holds for every bet on the table: the payout is always less than what the true odds would dictate, guaranteeing the casino a long-term profit. Even-money bets such as red or black illustrate this: on an American wheel you win 18 out of 38 spins, but the payout is only 1 to 1, not the true odds of 20 to 18 against.3
Where this term is used
Not the same as
- Roulette table — the physical layout with betting areas, not the probability/payout relationships
Related terms
Sources
- Roulette en.wikipedia.org Provides the definition of roulette odds, pocket counts, and payout ratios.
- Vigorish - Wikipedia en.wikipedia.org Explains how the house edge (vigorish) is created by the gap between true odds and payout.
- Gambling mathematics - Wikipedia en.wikipedia.org Supplies the specific probability for even-money bets on an American wheel (18/38).
- Odds - Wikipedia en.wikipedia.org Clarifies the distinction between true odds and payout odds in gambling.
- Roulette - FAQ wizardofodds.com Confirms the house edge for American roulette and the number of pockets.
- Roulette Basics – Rules, Bets, and Game Variations ... wizardofodds.com Provides the house edge percentages for both European and American roulette.
Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.