Before the comparison
Roulette is a game of chance with a built-in house edge on both wheel types. No strategy, system, pattern or timing changes the odds in the player’s favor over time, and most players lose money over time. Nobody should gamble money they cannot afford to lose. Comparing wheels shows which is costlier on average; neither is a way to profit. Anyone struggling with gambling can contact a local support service.
Counting the pockets
A single-zero wheel, often called European, has 37 pockets: the numbers 1 to 36 and one zero. A double-zero wheel, often called American, has 38 pockets: the numbers 1 to 36, a zero and a double zero (00). On both wheels, 18 of the numbers are red and 18 are black, and the zero pockets are green.
Nothing else changes in the standard game. The layout, the bet types and the usual payouts are identical, with a straight bet at 35 to 1, a corner at 8 to 1, an even-money bet at 1 to 1, and so on. Only the number of pockets differs, which means the same payouts are now paid against slightly lower chances of winning.
On the layout, the double-zero version shows both a 0 and a 00 at the top of the grid. Some places also use wheels with three zero pockets, which push the edge higher still.
The edge on a straight bet, by hand
Take a straight-up bet of 1 unit, paying 35 to 1.
Single zero. The bet wins on 1 pocket in 37 and loses on 36.
- Average result: (1 × 35 − 36 × 1) ÷ 37 = −1 ÷ 37 ≈ −0.0270.
- The house edge is about 2.70 percent.
Double zero. The bet wins on 1 pocket in 38 and loses on 37.
- Average result: (1 × 35 − 37 × 1) ÷ 38 = −2 ÷ 38 ≈ −0.0526.
- The house edge is about 5.26 percent.
The chance of winning a straight bet only moves from about 2.70 percent (1/37) to about 2.63 percent (1/38), a tiny change that is easy to overlook. But the payout stays at 35 to 1, so the cost to the player nearly doubles. The extra pocket adds one more losing outcome and no extra payout.
The same check for an even-money bet
A bet on red wins on 18 pockets on either wheel.
- Single zero: wins 18 of 37 (about 48.65 percent), loses 19 of 37. Average: (18 − 19) ÷ 37 = −1/37, about −2.70 percent.
- Double zero: wins 18 of 38 (about 47.37 percent), loses 20 of 38. Average: (18 − 20) ÷ 38 = −2/38, about −5.26 percent.
The edge is the same as for the straight bet on the same wheel, which is typical of standard bets. Whatever you bet on, the zero pockets set the cost.
What it means in money terms
A hypothetical illustration. Suppose someone stakes 1 unit on every one of 100 spins, with a total of 100 units wagered:
| Wheel | House edge | Average loss per 100 units staked |
|---|---|---|
| Single zero (37 pockets) | 1/37, about 2.70% | about 2.70 units |
| Double zero (38 pockets) | 2/38, about 5.26% | about 5.26 units |
The average loss on the double-zero wheel is roughly twice as large (5.26 ÷ 2.70 ≈ 1.95). Scale the stakes up or the number of spins up and the loss scales with them.
The averages hide real uncertainty. After 100 spins a player could be well ahead or well behind, and the law of large numbers only makes the average dependable across very large numbers of spins. The averages are not a forecast for any session, but they describe the price of playing.
One exception on the American layout
On many double-zero layouts there is an additional bet that covers five numbers: 0, 00, 1, 2 and 3. It typically pays 6 to 1. Hypothetically, with 1 unit staked it wins 6 on 5 pockets and loses 1 on 33: (5 × 6 − 33) ÷ 38 = −3 ÷ 38, about −7.89 percent. It is the one standard bet on that layout that costs noticeably more than the rest, a reminder that rules of a particular table matter.
Partial-return rules
Some tables return part of an even-money stake when zero lands. Where that applies, it lowers the edge on those bets, for example to about 1.35 percent on a single-zero wheel and about 2.63 percent on a double-zero wheel, if the rule covers both zero pockets. Rules vary by table, so rule transparency matters, and the posted rules should be checked before playing.
Why this matters for choosing a table
This is simple arithmetic: with the same bet and the same stake, the double-zero wheel costs about twice as much on average. That is a statement about cost, and not a suggestion that either table is a good way to spend money. A lower edge still means a loss on average, and a player who plays faster or bets more at the lower-edge table can easily lose more in total than one who plays slowly at the higher-edge one. What the player spends depends on both the edge and the amount staked, which is why fixed spending limits and a clear sense of the house edge are more useful than hunting for a favorable table.
Recognizing the wheel
The easiest check is to count the green pockets or look at the layout. If the grid shows 0 and 00, it is a double-zero game. If only a single 0 appears, it is a single-zero game. Online and streamed games usually state the type in their rules; if they do not, treat that as a reason to ask or to choose another game.