Roulette Probability Calculator
Calculate exact probabilities, expected values, and house edges for every roulette bet type. Visualize covered numbers on an interactive wheel and run multi-spin bankroll analysis.
Wheel TypeEuropean
Slots37
House Edge2.703%
Win Prob48.65%
Loss/Hour $16.22
Roulette Wheel
18 of 37 numbers covered (1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23, 25, 27, 30, 32, 34, 36)
Neighbour Bets (Number + Neighbours)
Select a number and how many neighbours on each side of the wheel. Each neighbour is a straight-up bet (1 chip each).
22517346
5 chips totalWin prob: 13.51% EV: -0.1351 per spin
Red Results
Win Probability48.6486% 18/37
Payout1:1 bet returned + 1x profit
House Edge2.703% European
Expected Value-0.0270per $1 wagered
Multi-Spin Analysis
Win at Least Once100.00% in 100 spins
Expected Bankroll $972.97after 100 spins
Prob. Being Ahead39.34% net profit > 0
Prob. Double Bankroll0.45% before going bust
Expected Wins48.6of 100 spins
Expected Profit$-27.03100 x $10
Std Deviation (1σ) ±$99.96after 100 spins
68% Range $-127 to $731σ profit band
Bankroll Lasts~3,700expected spins (theoretical)
All Bet Types Comparison: European
| Bet Type | Category | Numbers | Win Prob ▼ | Payout | House Edge | EV / $1 |
|---|---|---|---|---|---|---|
| Red | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| Black | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| Odd | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| Even | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| Low (1-18) | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| High (19-36) | Outside | 18 | 48.65% | 1:1 | 2.703% | -0.0270 |
| Voisins du Zero (9 chips, 17 nums) | French | 17 | 45.95% | 17:1 | 2.703% | -0.0270 |
| 1st Dozen (1-12) | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| 2nd Dozen (13-24) | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| 3rd Dozen (25-36) | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| 1st Column | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| 2nd Column | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| 3rd Column | Outside | 12 | 32.43% | 2:1 | 2.703% | -0.0270 |
| Tiers du Cylindre (6 chips, 12 nums) | French | 12 | 32.43% | 17:1 | 2.703% | -0.0270 |
| Orphelins (5 chips, 8 nums) | French | 8 | 21.62% | 17:1 | 2.703% | -0.0270 |
| Jeu Zero (4 chips, 7 nums) | French | 7 | 18.92% | 17:1 | 2.703% | -0.0270 |
| Six Line (1-6) | Inside | 6 | 16.22% | 5:1 | 2.703% | -0.0270 |
| Six Line (31-36) | Inside | 6 | 16.22% | 5:1 | 2.703% | -0.0270 |
| Corner (1-2-4-5) | Inside | 4 | 10.81% | 8:1 | 2.703% | -0.0270 |
| Corner (17-18-20-21) | Inside | 4 | 10.81% | 8:1 | 2.703% | -0.0270 |
| Street (1-2-3) | Inside | 3 | 8.11% | 11:1 | 2.703% | -0.0270 |
| Street (4-5-6) | Inside | 3 | 8.11% | 11:1 | 2.703% | -0.0270 |
| Street (34-35-36) | Inside | 3 | 8.11% | 11:1 | 2.703% | -0.0270 |
| Trio (0-1-2) | Inside | 3 | 8.11% | 11:1 | 2.703% | -0.0270 |
| Trio (0-2-3) | Inside | 3 | 8.11% | 11:1 | 2.703% | -0.0270 |
| Split (1-2) | Inside | 2 | 5.41% | 17:1 | 2.703% | -0.0270 |
| Split (17-20) | Inside | 2 | 5.41% | 17:1 | 2.703% | -0.0270 |
| Straight Up (0) | Inside | 1 | 2.70% | 35:1 | 2.703% | -0.0270 |
| Straight Up (17) | Inside | 1 | 2.70% | 35:1 | 2.703% | -0.0270 |
| Straight Up (32) | Inside | 1 | 2.70% | 35:1 | 2.703% | -0.0270 |
Understanding Roulette Mathematics
European vs American
European roulette has 37 pockets (0-36) with a 2.70% house edge. American roulette adds a double-zero (00) pocket, raising the total to 38 and nearly doubling the house edge to 5.26%. Always prefer European when available, it saves you 2.56% on every bet.
La Partage Rule
French roulette with La Partage returns half your stake on even-money bets (Red/Black, Odd/Even, High/Low) when the ball lands on zero. This cuts the house edge on those bets from 2.70% to just 1.35%, making them among the best bets in any casino. Non-even-money bets operate at the standard 2.70% European edge.
Expected Value Explained
Expected Value (EV) measures the average result per bet over the long run. An EV of -$0.027 on a $1 bet means you lose 2.7 cents per spin on average. While short-term results vary wildly, EV is inescapable over thousands of spins. No betting system can overcome a negative EV, the math always wins.
Called Bets (French)
French "called bets" cover specific wheel sectors: Voisins du Zero (17 numbers near zero), Tiers du Cylindre (12 numbers opposite zero), Orphelins (8 remaining numbers), and Jeu Zero (7 numbers closest to zero). These bets exploit the physical layout of the wheel rather than the table layout, offering a different way to group numbers.
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