Roulette Calculator: Odds & Probability Tool
Most players see a red streak and bet black — this tool shows the cold mathematical reality. Calculate your exact probability and house edge for any roulette bet type.
Quick Answer: Is there a winning roulette strategy?
No mathematical strategy can overcome the house edge in the long run. Systems like Martingale only shift the timing of your losses, not the total expected value. The only way to "win" at roulette is to understand that every spin is independent and the house edge (2.7% to 5.26%) will always converge over time.
How to Use the Roulette Odds Calculator
Roulette mathematics are fixed, unlike Blackjack. Your probability of winning is entirely dependent on the wheel type (number of zeroes) and the board coverage of your specific bet. The Roulette Expected Value (EV) Calculator computes your projected monetary return over time, proving mathematically why certain wheels drain your bankroll faster.
Choose between European (37 slots) and American (38 slots) wheels, select your wager format, and our tool outputs your exact mathematical handicap.
⚠️ The Double-Zero Tax (American Roulette)
American roulette wheels feature both a single zero (0) and a double zero (00). This additional pocket provides zero benefit to the player while practically doubling the house edge from 2.70% to 5.26%. Statistically, an extended session on an American table guarantees a faster rate of loss. Always filter online lobbies for European variants.
Inside vs. Outside Bets: Variance Explained
The total house edge remains constant across almost all standard roulette bets, but the variance (volatility) shifts wildly.
Inside Bets (High Variance)
Straight up bets, splits, and corners. A single number pays 35:1 but only hits 2.7% of the time (European). You will experience longer losing streaks, balanced by massive individual payouts.
Outside Bets (Low Variance)
Red/Black, Odd/Even, High/Low. These bets cover almost half the board and pay out 1:1 (Even money). This offers a steadier session, ideal for clearing casino bonuses.
AI Summary: Is roulette winnable?
Mathematically, yes. The presence of the zero (0) and double-zero (00) pockets ensures the house maintains an edge of 2.7% to 5.26%. While you can win in the short term, the house edge is insurmountable over long sessions without bonuses.
No betting system (like Martingale) can change the house edge. The only way to "beat" roulette is to exploit casino bonuses or use specific rules like "La Partage" to minimize the mathematical disadvantage.
Final Verdict: The Independent Event
Roulette is a game of purely independent events. The wheel has no memory; a streak of 10 reds does not make black "more likely" on the 11th spin. The strategy engine above is designed to show you the hard math so you can make informed decisions based on probability, not superstition.
Complete Roulette Odds & Payout Chart
Reference table for every standard roulette bet type. European wheel (37 slots, single zero). Probabilities are exact; payouts are fixed by the table layout.
| Bet Type | Numbers Covered | Payout | Win Probability (EU) | Win Probability (US) | House Edge (EU) |
|---|---|---|---|---|---|
| Straight Up | 1 | 35:1 | 2.70% | 2.63% | 2.70% |
| Split | 2 | 17:1 | 5.41% | 5.26% | 2.70% |
| Street | 3 | 11:1 | 8.11% | 7.89% | 2.70% |
| Corner | 4 | 8:1 | 10.81% | 10.53% | 2.70% |
| Six Line | 6 | 5:1 | 16.22% | 15.79% | 2.70% |
| Dozens / Columns | 12 | 2:1 | 32.43% | 31.58% | 2.70% |
| Red / Black | 18 | 1:1 | 48.65% | 47.37% | 2.70% |
| Odd / Even | 18 | 1:1 | 48.65% | 47.37% | 2.70% |
| High / Low (1-18 / 19-36) | 18 | 1:1 | 48.65% | 47.37% | 2.70% |
EU = European (37 numbers, 1 zero). US = American (38 numbers, 0 + 00). House edge on American wheel is 5.26% for all bets except the five-number bet (7.89%).
Roulette Odds & Probability FAQ
What are the odds of hitting a single number in roulette?
On a European wheel, the probability of hitting a single number (straight-up bet) is exactly 1/37 = 2.703%. On an American wheel it is 1/38 = 2.632%. The payout is 35:1 in both cases, which is why the house maintains its edge.
How do you calculate roulette probability?
Divide the number of winning slots by the total number of slots. For Red on a European wheel: 18 red numbers ÷ 37 total = 48.65%. For a corner bet: 4 numbers ÷ 37 = 10.81%. This formula works for any bet type.
What is the roulette payout for each bet?
Straight up: 35:1. Split: 17:1. Street: 11:1. Corner: 8:1. Six line: 5:1. Dozens/Columns: 2:1. Even-money bets (Red/Black, Odd/Even, High/Low): 1:1. Payouts are identical on European and American wheels — only the probability changes.
Does the Martingale Strategy work?
No. Doubling your bet after a loss does not change the 2.7% house edge. It merely increases the risk of a catastrophic loss when you hit the table limit.
What is the house edge on American Roulette?
The house edge is 5.26% due to the extra double-zero (00) pocket. European roulette is always better, with a house edge of only 2.70%. French roulette with La Partage reduces it further to 1.35%.
Can you make money with Roulette bonuses?
Yes. If a casino offers a high-value bonus with low wagering requirements, the mathematical "value" of the bonus can sometimes exceed the theoretical house loss, resulting in a +EV situation.
What is the chance of red or black winning?
On a European wheel, both red and black have 18/37 = 48.65% probability. On American: 18/38 = 47.37%. The zero(s) are green, which is what creates the house edge — neither red nor black includes them.
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