European Roulette uses a single-zero wheel with 37 slots, giving you the best odds in standard roulette. This guide covers every bet type, exact probabilities, payouts, and the special rules that can cut the house edge in half. All math is shown so you can verify it yourself.
European Roulette Cheat Sheet
| Bet Type | Payout | Probability | Covers |
|---|---|---|---|
| Straight Up | 35:1 | 2.70% | 1 number |
| Split | 17:1 | 5.41% | 2 numbers |
| Street | 11:1 | 8.11% | 3 numbers |
| Corner | 8:1 | 10.81% | 4 numbers |
| Line | 5:1 | 16.22% | 6 numbers |
| Column / Dozen | 2:1 | 32.43% | 12 numbers |
| Even Money | 1:1 | 48.65% | 18 numbers |
How European Roulette Works
A European roulette wheel has 37 numbered slots: the numbers 1 through 36 (alternating red and black) plus a single green zero (0). The croupier spins the wheel in one direction and rolls a ball in the other. When the ball comes to rest in a numbered pocket, all bets covering that number are paid according to fixed payout ratios.
The single zero is what creates the house edge. All payouts are calculated as if there were only 36 numbers, but there are actually 37. That extra slot is the casino’s profit margin.
This is the key difference from American Roulette, which has 38 slots (adding a double zero, 00). That second zero nearly doubles the house edge from 2.70% to 5.26%. Some casinos even offer triple-zero wheels at 7.69% — avoid those entirely.
French Roulette uses the same 37-number wheel but adds special rules (La Partage and En Prison) that further reduce the house edge on even-money bets. We cover these in detail below.
European Roulette Payout & Odds Chart
Every bet in European roulette has the same house edge of 2.70%. The difference between bets is the risk-reward tradeoff: inside bets cover fewer numbers for higher payouts, while outside bets cover more numbers for smaller returns.
| Bet | Numbers Covered | Payout | Probability | Odds (1 in X) |
|---|---|---|---|---|
| Inside Bets | ||||
| Straight Up | 1 | 35:1 | 2.70% | 1 in 37.0 |
| Split | 2 | 17:1 | 5.41% | 1 in 18.5 |
| Street | 3 | 11:1 | 8.11% | 1 in 12.3 |
| Corner | 4 | 8:1 | 10.81% | 1 in 9.3 |
| Line (Double Street) | 6 | 5:1 | 16.22% | 1 in 6.2 |
| Outside Bets | ||||
| Column | 12 | 2:1 | 32.43% | 1 in 3.1 |
| Dozen (1–12, 13–24, 25–36) | 12 | 2:1 | 32.43% | 1 in 3.1 |
| Red / Black | 18 | 1:1 | 48.65% | 1 in 2.1 |
| Odd / Even | 18 | 1:1 | 48.65% | 1 in 2.1 |
| High (19–36) / Low (1–18) | 18 | 1:1 | 48.65% | 1 in 2.1 |
Inside Bets Explained
Inside bets are placed on specific numbers or small groups of numbers on the numbered grid of the table layout. They offer higher payouts but lower probabilities of winning.
Outside Bets Explained
Outside bets are placed on the areas around the numbered grid. They cover larger groups of numbers and hit more frequently, but pay less. These are the bets most players start with because the win rate is close to 50%.
House Edge & Expected Value
Every bet on a standard European roulette table has the same house edge: 2.70%. This means for every $100 you wager over time, you can expect to lose $2.70 on average. The expected return is 97.30%.
Here’s the logic: a straight-up bet on a single number has true odds of 36 to 1 (there are 36 other numbers), but the casino only pays 35 to 1. That missing unit, spread across 37 possible outcomes, gives the house its 2.70% edge. The same math applies to every bet on the table.
EV = $48.65 − $51.35
EV = −$2.70
This is a long-run average. In any single session, variance dominates — you can win big or lose fast. But over thousands of spins, results converge on the expected value. If you want to explore how variance affects your results in games of chance, our Poker Variance Calculator demonstrates the same mathematical concepts applied to poker.
La Partage & En Prison Rules
These are special rules found at some European and French roulette tables. They only apply to even-money bets (red/black, odd/even, high/low) and they significantly reduce the house edge.
La Partage (“The Divide”)
If the ball lands on zero while you have an even-money bet, you get half your stake back instead of losing it all. For example, a $20 bet on red that loses to zero returns $10 to you.
En Prison (“In Prison”)
If the ball lands on zero, your even-money bet is “imprisoned” for the next spin rather than lost. If the next spin wins for your bet, you get your full stake back (but no additional winnings). If it loses, your bet is forfeited. If zero hits again, the bet stays imprisoned for another spin (rules vary by casino).
The math works out to the same 1.35% house edge as La Partage. The difference is psychological: with En Prison you have a chance to recover your full bet rather than automatically losing half.
Probability Over Multiple Spins
Single-spin probabilities tell part of the story. Over multiple spins, the question changes to: “What are the chances of winning at least once in N spins?” or “What are the odds of a streak?”
Winning at Least Once in N Spins (Straight-Up Bet)
To find the probability of hitting your number at least once, calculate the chance of missing every time and subtract from 1.
P(lose 10 spins) = (36/37)¹⁰ = 0.7526 = 75.26%
P(win at least once in 10) = 1 − 0.7526 = 24.74%
| Number of Spins | P(Hit at Least Once) | P(Miss Every Spin) |
|---|---|---|
| 5 spins | 12.85% | 87.15% |
| 10 spins | 24.74% | 75.26% |
| 20 spins | 42.34% | 57.66% |
| 37 spins | 63.67% | 36.33% |
| 50 spins | 74.69% | 25.31% |
| 100 spins | 93.54% | 6.46% |
| 200 spins | 99.58% | 0.42% |
Note the 37-spin row: even after the same number of spins as there are slots on the wheel, there’s still only a 63.67% chance of hitting your number at least once. This surprises many players who expect a roughly 1-in-37 event to happen within 37 attempts.
Consecutive Wins on Even-Money Bets
The probability of consecutive wins (or losses) on even-money bets like red/black:
| Consecutive Wins | Probability | Odds (1 in X) |
|---|---|---|
| 2 in a row | 23.67% | 1 in 4.2 |
| 3 in a row | 11.52% | 1 in 8.7 |
| 5 in a row | 2.73% | 1 in 36.6 |
| 7 in a row | 0.65% | 1 in 154.9 |
| 10 in a row | 0.07% | 1 in 1,346 |
Same Number Hitting Twice in a Row
The probability of the exact same number appearing on two consecutive spins:
This happens about once every 1,369 spin pairs. Rare, but not impossible — in a busy casino running 80 spins per hour, you’d expect to see it roughly once every 17 hours on a single table.
Betting Strategies
No betting system can overcome the house edge in the long run. The math is unambiguous on this point. However, strategies can affect your short-term variance profile — how your bankroll swings during a session. Here are the most common systems and what they actually do.