Short answer: a European roulette wheel has 37 pockets, so a single number wins 1 time in 37 and red wins 18 times in 37. Every bet pays slightly less than its true odds, which is how the casino earns a 2.70% edge on every bet (5.26% on American wheels). Use the calculator below to see the odds of any bet.
Odds, probability and payouts: three different things
- Probability is how often a bet wins, e.g. red wins 18 out of 37 spins, or 48.65%.
- True odds compare losing outcomes to winning ones. A single number has 36 losing pockets and 1 winning one, so true odds are 36 to 1.
- Payout is what the casino actually pays: 35 to 1 for a single number. That one-unit gap between true odds and payout is the house edge.
Roulette odds calculator
The top line bet only exists on American wheels, so the calculator switched to American.
- Chance to win
- –
- If it wins
- –
- House edge
- –
- Expected loss per 100 bets
- –
Every bet at a glance (European wheel)
| Bet | Numbers | Pays | True odds | Wins about |
|---|---|---|---|---|
| Straight up | 1 | 35:1 | 36:1 | 1 in 37 |
| Split | 2 | 17:1 | 17.5:1 | 1 in 18.5 |
| Street | 3 | 11:1 | 11.33:1 | 1 in 12.3 |
| Corner | 4 | 8:1 | 8.25:1 | 1 in 9.25 |
| Six line | 6 | 5:1 | 5.17:1 | 1 in 6.2 |
| Dozen or column | 12 | 2:1 | 2.08:1 | 1 in 3.1 |
| Red/black, odd/even, high/low | 18 | 1:1 | 1.06:1 | 1 in 2.06 |
On an American wheel every bet loses one more pocket to the 00, so the house edge rises to 5.26%. See European vs American roulette odds for the full comparison.
Why every bet has the same house edge
Roulette payouts are set as if the wheel had only 36 numbers. Add the green zero and every bet loses the same share of its value: 1 in 37, or 2.70%. That's why no combination of bets, from "cover the whole table" to French call bets like Voisins du Zéro or Tiers du Cylindre, changes the average result. They're just bundles of splits, streets and corners, each with the same 2.70% edge.
What does change is the shape of your results. Even-money bets win often and pay little, so your balance moves slowly. Single numbers rarely win but pay big, so your balance swings hard. Pick the ride you enjoy; the cost is the same.
How often should a number come up?
On average, any single number appears once every 37 spins, but "on average" hides a lot of variation:
- Within 37 spins, a given number comes up at least once only 63.7% of the time.
- About 6.5% of the time, a number goes 100 spins without appearing at all.
- Red comes up 5 times in a row about once every 37 tries, and 10 times in a row about once every 1,347.
Streaks and "cold" numbers are normal. After five reds in a row, red's chance on the next spin is still exactly 48.65%. The wheel has no memory. More on that in Is online roulette rigged?
Frequently asked questions
What does "35 to 1" mean?
For every €1 you bet you win €35 and keep your €1, so €36 comes back to you. True odds on a European wheel are 36 to 1; the missing unit is the casino's edge.
Is betting on red safer than a single number?
It wins far more often, so your money lasts longer and swings less. It isn't cheaper: both lose 2.70% of what you bet on average.
Can I test betting systems with these odds?
Yes. The free roulette simulator uses exactly these odds and lets you run 1,000 sessions of Martingale, Paroli, D'Alembert, Fibonacci or flat betting.