Roulette Odds Calculator: Complete Probability Guide (2026)
Roulette Odds Calculator: Know Your Probabilities for Every Bet
Roulette combines simple gameplay with complex probability. Every bet type has different odds, payouts, and house edges. Our free roulette odds calculator shows you exact probabilities for any bet on any wheel type, helping you understand exactly what you're up against.
What Are Roulette Odds?
Roulette odds represent the probability of winning each bet type, based on how many numbers you cover out of the total numbers on the wheel.
Quick Answer: Roulette odds depend on how many numbers your bet covers. A straight bet on one number has 1/37 (2.7%) odds in European roulette. A red/black bet covers 18 numbers, giving you 18/37 (48.6%) odds. The house always has an edge because green zero(s) aren't covered by outside bets.
How to Use Our Free Roulette Odds Calculator
Use the Roulette Odds Calculator →
Select your wheel type and bet type to see exact odds, payouts, and house edge.
Step-by-Step Instructions
-
Select Wheel Type: Choose European (single zero), American (double zero), or French
-
Choose Bet Type: Select from inside or outside bets
-
View Probabilities: See your exact win percentage and payout
-
Compare House Edge: Understand the casino's advantage on each bet
Input Fields Explained
| Field | Description | Example |
|---|---|---|
| Wheel Type | European, American, or French | European (single zero) |
| Bet Type | Inside or outside bet | Red/Black |
| Bet Amount | How much you're wagering | $10 |
Roulette Wheel Differences
European Roulette (Single Zero)
- Numbers: 0-36 (37 total)
- House Edge: 2.70%
- Best choice for players
American Roulette (Double Zero)
- Numbers: 0, 00, 1-36 (38 total)
- House Edge: 5.26%
- Avoid when European is available
French Roulette
- Numbers: 0-36 (37 total)
- House Edge: 1.35% (with La Partage rule)
- Best odds in roulette
Complete Roulette Odds Chart
Inside Bets
| Bet Type | Numbers Covered | European Odds | American Odds | Payout |
|---|---|---|---|---|
| Straight (Single Number) | 1 | 2.70% | 2.63% | 35:1 |
| Split (Two Numbers) | 2 | 5.41% | 5.26% | 17:1 |
| Street (Three Numbers) | 3 | 8.11% | 7.89% | 11:1 |
| Corner (Four Numbers) | 4 | 10.81% | 10.53% | 8:1 |
| Six Line (Six Numbers) | 6 | 16.22% | 15.79% | 5:1 |
| Basket (American Only) | 5 | N/A | 13.16% | 6:1 |
Outside Bets
| Bet Type | Numbers Covered | European Odds | American Odds | Payout |
|---|---|---|---|---|
| Red/Black | 18 | 48.65% | 47.37% | 1:1 |
| Odd/Even | 18 | 48.65% | 47.37% | 1:1 |
| High/Low (1-18/19-36) | 18 | 48.65% | 47.37% | 1:1 |
| Dozens (1-12, 13-24, 25-36) | 12 | 32.43% | 31.58% | 2:1 |
| Columns | 12 | 32.43% | 31.58% | 2:1 |
Real-World Roulette Examples
Example 1: Red/Black Bet Analysis
You bet $10 on red at a European roulette table.
The Math:
- Win probability: 18/37 = 48.65%
- Lose probability: 19/37 = 51.35%
- Expected value: (0.4865 × $10) - (0.5135 × $10) = -$0.27
Result: On average, you lose 2.7% of your bet ($0.27 per $10) over time. This is the house edge working.
Example 2: Straight Bet Risk
You bet $5 on number 17 at an American roulette table.
The Math:
- Win probability: 1/38 = 2.63%
- Win amount: $5 × 35 = $175 profit
- Expected value: (0.0263 × $175) - (0.9737 × $5) = $4.60 - $4.87 = -$0.27
Result: Even with a 35:1 payout, the house edge makes this bet -EV. The payout should be 37:1 to be fair.
Example 3: Comparing Wheel Types
You want to bet $100 on even numbers for one hour (60 spins).
European Wheel:
- House edge: 2.70%
- Expected loss: $100 × 60 × 0.027 = $162
American Wheel:
- House edge: 5.26%
- Expected loss: $100 × 60 × 0.0526 = $316
Difference: You save $154/hour by playing European roulette!
House Edge Explained
The house edge comes from the zero pockets. When you bet red/black, you cover 18 numbers but there are 37 (or 38) total numbers:
European: House edge = 1/37 = 2.70% American: House edge = 2/38 = 5.26%
The payout ratios assume no zeros exist. A "fair" straight bet would pay 36:1 (European) or 37:1 (American), but casinos pay 35:1.
Special Rules That Help Players
La Partage (French Roulette)
If the ball lands on zero, you get half your even-money bet back.
Effect: Cuts house edge on even-money bets to 1.35%
En Prison (French Roulette)
If the ball lands on zero, your even-money bet is "imprisoned." If it wins on the next spin, you get it back (no profit). If it loses, you lose it.
Effect: Similar to La Partage—house edge reduced to 1.35%
Surrender (Some American Tables)
Some American casinos offer surrender on even-money bets when zero or double-zero hits.
Effect: Reduces house edge from 5.26% to 2.63% on even-money bets
Common Roulette Odds Mistakes
-
Believing in "Due" Numbers: If red hits 10 times in a row, red is not "due." Each spin is independent. The odds remain exactly the same.
-
Playing American Over European: When both are available, European is always mathematically superior. The difference is nearly double the house edge.
-
Ignoring the Long Run: Short-term variance can make roulette feel beatable. Over thousands of spins, the house edge will prevail.
-
Betting Systems as Solutions: Martingale, Fibonacci, and other systems don't change expected value. They just change the distribution of wins and losses.
-
Thinking Inside Bets Are Better: Inside bets feel exciting but have the same house edge as outside bets (in most cases). The basket bet in American roulette is actually worse (7.89% edge).
Frequently Asked Questions
What's the best bet in roulette?
On European/French wheels, all bets have the same 2.70% house edge except La Partage bets (1.35%). On American wheels, avoid the basket bet (7.89% edge). Otherwise, all bets have equal expected value.
Can I beat roulette with a betting system?
No betting system changes the fundamental house edge. Martingale, Fibonacci, D'Alembert, and others simply restructure variance. In the long run, the house edge applies regardless of bet sizing patterns.
Why is European roulette better than American?
European has one zero (2.70% edge). American has two zeros (5.26% edge). That's nearly double the disadvantage for players. Always choose European when available.
What are the odds of red hitting 10 times in a row?
In European roulette: (18/37)^10 = 0.074% or about 1 in 1,350. Rare but not remarkable over thousands of spins.
Is there a way to predict roulette numbers?
Legitimate prediction requires identifying a biased wheel (physically imperfect) or dealer signature (consistent spin patterns). Modern casinos use high-quality equipment that makes these methods nearly impossible.
Are online roulette odds fair?
Licensed online casinos use Random Number Generators (RNGs) that replicate true odds. Stick to regulated, audited casinos. The odds should match physical wheel probabilities.
Roulette Probability Quick Reference
| Outcome | European | American |
|---|---|---|
| Specific number | 2.70% | 2.63% |
| Any single number wins | 2.70% | 2.63% |
| Red or Black | 48.65% | 47.37% |
| Odd or Even | 48.65% | 47.37% |
| Zero (any) | 2.70% | 5.26% |
| Same color 5× in row | 2.60% | 2.37% |
| Same number 2× in row | 0.073% | 0.069% |
Pro Tips for Roulette Players
-
Always Play European: If you have a choice, European's lower house edge saves money over time
-
Look for La Partage Rules: French roulette with La Partage has the lowest house edge in roulette
-
Set Loss Limits: Roulette is negative EV. Set strict limits and consider it entertainment cost
-
Avoid the Basket Bet: On American wheels, the 5-number basket bet has the worst odds (7.89% edge)
-
Understand Variance: Even-money bets have lower variance (more consistent results). Inside bets have high variance (bigger swings)
The Math Behind Roulette Payouts
Roulette payouts are designed to be slightly unfair:
Fair payout formula: (36 / numbers covered) - 1
Actual payouts are lower:
- Straight: Should pay 36:1 (European), pays 35:1
- Split: Should pay 17.5:1, pays 17:1
- This shortfall creates the house edge
If casinos paid true odds with zero included:
- Straight bet: 36:1 (European) or 37:1 (American)
- The game would be exactly fair (0% house edge)
Related Casino Calculators
- Roulette House Edge Calculator - Compare wheel types
- Roulette EV Calculator - Expected value analysis
- Roulette Payout Calculator - Calculate winnings
- Roulette Betting Simulator - Test systems
- Roulette Probability Calculator - Streak analysis
Conclusion
Roulette odds are straightforward once you understand the math. Every bet has a house edge, every spin is independent, and no system beats the math. Our free roulette odds calculator shows you exact probabilities for any bet type on any wheel.
Calculate Your Roulette Odds Now →
Play European roulette, understand the probabilities, set strict limits, and enjoy roulette for what it is—an exciting game of chance with well-defined odds.
