Roulette Probability Reference
Payouts, true odds and house edge for European and American roulette.
Overview
The Roulette Probability Reference shows payouts, true odds, and house edge for every standard bet on European (single-zero) and American (double-zero) roulette. It's the at-a-glance reference for understanding why some bets feel even-money but quietly bleed your bankroll, and why European roulette is the better game whenever you have the choice.
The reference also visualises the house edge per bet, which is the long-run percentage of every wagered dollar that goes to the casino. European roulette has a uniform 2.7 percent edge on most bets; American roulette has a uniform 5.26 percent on most bets due to the extra 00 pocket; and the American five-number bet (0-00-1-2-3) has an even worse 7.89 percent edge.
How it works
Each bet's true odds are the ratio of "win" pockets to "lose" pockets on the wheel. The casino pays out at slightly less than true odds, and the gap is the house edge. For example, a single-number bet on European roulette wins on 1 of 37 pockets — true odds 36 to 1 — but the casino pays 35 to 1, so the house keeps 1 unit out of every 37 wagered (1/37 = 2.7 percent).
The bet table covers straight-up (one number), splits (two), streets (three), corners (four), six-line (six), columns (twelve), dozens (twelve), red/black, odd/even, and high/low. The American wheel adds the 00 pocket, which is not red/black/odd/even, so even-money bets lose on both 0 and 00 — doubling the house edge on those wagers.
Examples
- European single-number bet: true odds 36:1, payout 35:1, house edge 2.7 percent.
- American single-number bet: true odds 37:1, payout 35:1, house edge 5.26 percent.
- European red bet: 18 of 37 pockets win, payout 1:1, house edge 2.7 percent.
- American five-number bet (0, 00, 1, 2, 3): payout 6:1, true odds 33:5 = 6.6:1, house edge 7.89 percent.
FAQ
Which roulette has a better house edge?
European, at 2.7 percent. American is essentially double that on most bets.
Are betting systems like Martingale profitable?
No. They redistribute variance — short-term wins, occasional catastrophic losses. Expected value is unchanged.
What's "en prison" or "la partage"?
Rules that halve the house edge on even-money bets when 0 hits. Available on some European tables, dropping the edge to 1.35 percent.
Why does the five-number bet have a worse edge?
The mathematically correct payout for 5/38 is 6.6:1 but the casino pays 6:1, creating a larger gap.
Is roulette beatable?
Only if the wheel is biased or a dealer signature is exploitable. Properly maintained modern wheels are unbeatable in the long run.