Roulette · Probability
A wider bet wins more often, not more profitably
On a European wheel, a single number wins with probability 1/37, about 2.70%. Red covers 18 pockets, so its probability is 18/37, about 48.65%. The previous spin does not change either probability.
The standard house edge is about 2.70% for European roulette and 5.26% for most American bets. The American first-five bet is an exception at about 7.89%. French La Partage reduces the edge on eligible even-money bets to about 1.35%.
Expected loss describes a long-run average across many wagers, not the result of any particular session. A short session may finish ahead or behind by much more than that average.
Roulette payouts and winning probabilities
| Bet types | Numbers covered | Profit payout | Return for 10 chips | Chance of winning |
|---|---|---|---|---|
| Single number | 1 | 35:1 | 360 | 1/37 ≈ 2.7% |
| Split | 2 | 17:1 | 180 | 2/37 ≈ 5.41% |
| Street | 3 | 11:1 | 120 | 3/37 ≈ 8.11% |
| Trio | 3 | 11:1 | 120 | 3/37 ≈ 8.11% |
| Corner | 4 | 8:1 | 90 | 4/37 ≈ 10.81% |
| Basket | 4 | 8:1 | 90 | 4/37 ≈ 10.81% |
| Six line | 6 | 5:1 | 60 | 6/37 ≈ 16.22% |
| Column | 12 | 2:1 | 30 | 12/37 ≈ 32.43% |
| Dozen | 12 | 2:1 | 30 | 12/37 ≈ 32.43% |
| Red | 18 | 1:1 | 20 | 18/37 ≈ 48.65% |
Profit excludes the original stake. The total return includes it. For example, a winning 10-chip single-number bet returns 360 chips: 350 profit plus the 10-chip stake. On French even-money bets, zero returns 5 of a 10-chip stake; that is a partial loss, not a win.
Play roulette simulator ↗European vs American vs French roulette
| Variant | Pockets | Zero pockets | House edge | Zero rule |
|---|---|---|---|---|
| European | 37 | 0 | 2.7% | Outside bets lose |
| American | 38 | 0, 00 | 5.26% | Outside bets lose |
| French | 37 | 0 | 2.7% / 1.35% | La Partage |
The American first-five bet is an exception: its house edge is 7.89%. French La Partage reduces the edge to 1.35% only on even-money bets; other standard bets remain at 2.70%. These percentages describe average loss per amount wagered, not the chance of losing a spin.
Sources and calculations
These references support the topics listed below. Explanations and simulator examples are written by Simulator Lab. Numerical examples are calculations by Simulator Lab using the stated rules and assumptions.
- Journal de Monaco — Arrêté ministériel n° 2009-595 FR ↗
Sections 1.2 and 1.5: 37 pockets, standard payouts and the half-stake return on zero.
- The Venetian — Roulette Rules EN ↗
Standard European/American wheels and payouts, including 6:1 for 0/00/1/2/3.
- GambleAware NSW — Casinos EN ↗
Common myths: previous losses do not make a roulette win due; betting patterns do not control results.
Sources checked: