There are two roulette wheels in serious casino circulation: the European wheel, with 37 pockets (numbered 0 through 36), and the American wheel, with 38 (the same numbers plus a 00). Side by side, the difference looks cosmetic — one extra green slot. The math difference is anything but cosmetic. The European wheel charges a 2.70% house edge. The American wheel charges 5.26%. Same game, same bets, same payouts. Almost double the cost.
This article walks through where that gap comes from, why the 'even-money' bets aren't actually 50/50, and where you can still find a European wheel in a US casino.
The two wheels at a glance
European roulette: 37 pockets. One green (0), 18 red, 18 black. The numbers 1-36 are split evenly between red and black, alternating high/low and even/odd in a specific sequence designed to balance the wheel mechanically.
American roulette: 38 pockets. Two green (0 and 00), 18 red, 18 black. Same 1-36 numbers but the green double-zero is added directly opposite the single zero.
The payouts are identical on both wheels. A straight-up bet (one number) pays 35:1. A split pays 17:1. A column or dozen pays 2:1. An even-money bet (red/black, odd/even, high/low) pays 1:1.
The house-edge math, bet by bet
Straight-up bet on the European wheel: 1/37 chance of winning 35 units, 36/37 chance of losing 1 unit. Expected value per $1 bet:
- 1/37 × +$35 = +$0.9459
- 36/37 × −$1 = −$0.9730
- Sum: −$0.0270
- House edge: 2.70%
Same bet on the American wheel: 1/38 chance of winning 35 units, 37/38 chance of losing 1 unit.
- 1/38 × +$35 = +$0.9211
- 37/38 × −$1 = −$0.9737
- Sum: −$0.0526
- House edge: 5.26%
The only difference is the denominator. The American wheel has one more losing slot for you, so each bet's expected value drops by about 2.56 percentage points. Multiply that by every spin you make and the gap compounds fast.
Why 'even-money' bets aren't 50/50
The most common roulette bet is red/black. It pays 1:1 and looks like a coin flip. It's not. On a European wheel, the probability of winning red/black is 18/37 = 48.65%. On American, it's 18/38 = 47.37%. The green pocket(s) belong to neither color, so the casino keeps every wager when a 0 (or 00) hits.
This is the entire roulette business model. Casinos pay you as if the bets were 50/50 propositions; the green pockets are the margin. The European wheel has one such pocket; American has two. That's why the edges are 2.70% and 5.26%. The math is that simple.
La Partage and En Prison: the 1.35% footnote
Some European casinos offer rules that further cut the house edge on even-money bets:
- La Partage: if zero rolls, even-money bets lose only half — the casino returns 50% of the stake
- En Prison: if zero rolls, the bet is 'imprisoned' for one more spin. Wins next spin → returned. Loses next spin → casino keeps it
Either rule cuts the house edge on red/black (and the other even-money bets) from 2.70% to 1.35% — putting it in the same neighborhood as basic-strategy blackjack. These rules are standard in French casinos and a few Monte Carlo tables. They are extremely rare in the US.
Where to find a European wheel in the US
Most US casinos run American wheels exclusively on the main floor. European wheels exist but are usually behind a velvet rope:
- High-limit rooms at major Strip casinos — often $25 or $50 minimum, often single-zero
- Some Macau-themed casino areas (e.g. Wynn, Cosmopolitan high-limit)
- European-themed riverboat casinos in the Midwest occasionally
- Online casinos can offer European wheels at any stake — verify the wheel before you bet
If your local card room has only American roulette and you don't want to play 5.26%, the right answer is to not play roulette there. Switch to blackjack, baccarat, or the Pass Line — all under 1.5% edge with normal rules.
The Martingale doesn't care which wheel
A common pitch around roulette is that 'with the right betting system, the house edge doesn't matter.' This is false on both wheels. The Martingale (double after every loss until you win) eventually fails because the table maximum limits how many doubles you can string together — and the streak of losses needed to bust you is statistically inevitable on a long enough timeline.
Worse, the Martingale doesn't change the EV of any individual bet. You're still betting 1.35% (best case, French rules) to 5.26% (American) per dollar wagered. The system just changes the distribution: most sessions you win a little, occasional sessions you lose a lot, and the lifetime average is exactly the house edge times your total action.
The quick-look comparison
If you must play roulette, find a European wheel. If you can't find one, find a different game.