Roulette odds come from one simple question: how many pockets make your bet win, and how many pockets are on this wheel? Once those two numbers are known, the hit probability is fixed. The payout then determines whether the wager is fairly priced or gives the casino an advantage.
That distinction matters because players often mix up three different ideas: chance to win, payout, and house edge. A red bet wins far more often than a straight-up number, but on a standard wheel both are normally priced to the same house edge. A single-zero wheel and a double-zero wheel can also offer the same printed payout while producing materially different expected losses.
Start with the denominator: 37 pockets or 38
A conventional single-zero wheel contains numbers 1 through 36 plus 0, for 37 total pockets. A conventional American double-zero wheel adds 00, making 38 pockets. If each pocket is equally likely, the probability of any ordinary roulette wager is:
Probability = winning pockets / total wheel pockets
So a straight-up number is 1/37 on a single-zero wheel and 1/38 on a double-zero wheel. Red covers 18 numbers, so it is 18/37 or 18/38. A dozen covers 12 numbers, so it is 12/37 or 12/38.
This denominator is why wheel selection matters before any betting system, color preference, or number-picking method. The extra 00 does not look dramatic, but it is an additional losing outcome for most conventional wagers without a compensating increase in the standard payout.
For a direct wheel comparison, see European vs American roulette. For the casino-price interpretation, see roulette house edge.
Single-zero probability and payout reference
The standard single-zero table below uses 37 pockets and the conventional live-roulette payout schedule.
| Wager | Winning pockets | Hit probability | Standard payout | Standard house edge |
|---|---|---|---|---|
| Straight-up | 1 | 2.70% | 35 to 1 | 2.70% |
| Split | 2 | 5.41% | 17 to 1 | 2.70% |
| Street | 3 | 8.11% | 11 to 1 | 2.70% |
| Corner | 4 | 10.81% | 8 to 1 | 2.70% |
| Six-line | 6 | 16.22% | 5 to 1 | 2.70% |
| Dozen | 12 | 32.43% | 2 to 1 | 2.70% |
| Column | 12 | 32.43% | 2 to 1 | 2.70% |
| Red / Black | 18 | 48.65% | 1 to 1 | 2.70% |
| Odd / Even | 18 | 48.65% | 1 to 1 | 2.70% |
| 1–18 / 19–36 | 18 | 48.65% | 1 to 1 | 2.70% |
The key pattern is not that every bet wins equally often. They plainly do not. The pattern is that the conventional payouts are calibrated so these ordinary bets share the same single-zero edge.
Official live-roulette rules commonly list the familiar schedule: 35:1 straight, 17:1 split, 11:1 street, 8:1 corner, 5:1 six-line, 2:1 dozen/column, and 1:1 on even-money wagers. See the Nevada Live Roulette rules of play and the Massachusetts roulette rules for regulated examples.
Double-zero probability reference: same payout, worse price
On a conventional 38-pocket wheel, the same wager covers a slightly smaller fraction of the possible outcomes.
| Wager | Winning pockets | Hit probability | Standard payout | Standard house edge |
|---|---|---|---|---|
| Straight-up | 1 | 2.63% | 35 to 1 | 5.26% |
| Split | 2 | 5.26% | 17 to 1 | 5.26% |
| Street | 3 | 7.89% | 11 to 1 | 5.26% |
| Corner | 4 | 10.53% | 8 to 1 | 5.26% |
| Six-line | 6 | 15.79% | 5 to 1 | 5.26% |
| Dozen | 12 | 31.58% | 2 to 1 | 5.26% |
| Column | 12 | 31.58% | 2 to 1 | 5.26% |
| Red / Black | 18 | 47.37% | 1 to 1 | 5.26% |
| Odd / Even | 18 | 47.37% | 1 to 1 | 5.26% |
| 1–18 / 19–36 | 18 | 47.37% | 1 to 1 | 5.26% |
The visual difference between one green pocket and two can look small. The mathematical difference is not. For a $10 red wager, the expected loss is about $0.27 on the ordinary single-zero game and about $0.53 on the ordinary double-zero game.
That is why the phrase “red pays even money on both” is incomplete. The payout is the same; the chance of winning is not.
Payout is not probability, and probability is not house edge
Consider three conventional single-zero wagers:
- Straight-up: wins about 2.70% of spins and pays 35:1.
- Corner: wins about 10.81% of spins and pays 8:1.
- Red: wins about 48.65% of spins and pays 1:1.
The straight-up wager has the rarest hit and the largest payout. Red has the most frequent hit and the smallest payout. Yet under the standard paytable they all produce the same 2.70% house edge.
This is the reason “bet on something that wins more often” does not automatically mean “choose a cheaper roulette wager.” Hit frequency changes the shape of the ride. The paytable determines the price of the ride.
For a deeper payout comparison, use roulette payouts and why most roulette bets have the same house edge.
Why even-money bets are not true 50/50 propositions
Red, black, odd, even, 1–18, and 19–36 each cover 18 of the numbered pockets. They are called even-money bets because a standard win pays 1:1, not because the chance is exactly 50%.
On a single-zero wheel:
P(red) = 18 / 37 = 48.6486%
There are 18 red wins and 19 non-red outcomes when zero is included.
On a double-zero wheel:
P(red) = 18 / 38 = 47.3684%
There are 18 red wins and 20 non-red outcomes because both 0 and 00 are green.
The same logic applies to odd/even and high/low. Zero is neither odd nor even, neither high nor low, and neither red nor black. Double zero adds another non-winning pocket on the conventional American wheel.
French protection changes settlement, not the wheel count
French-style rules such as La Partage or En Prison can improve eligible even-money bets on a single-zero wheel. The important point is that these are settlement rules applied after zero; they do not turn every roulette wager into a lower-edge bet.
Under La Partage, an eligible even-money wager loses only half when zero lands. That reduces the long-run edge from about 2.70% to about 1.35%. En Prison can produce a similar expected-value result under the standard French treatment, although exact imprisonment procedure can vary by house.
Inside bets such as straight-ups, splits, streets, and corners do not automatically receive that protection. A player who sees “French roulette” should therefore check the actual rule card rather than assume every betting box is half-price.
For the procedural details, see La Partage and En Prison. The Wizard of Odds roulette rules analysis also separates the single-zero base game from French half-loss and imprisonment treatment.
One major American exception: the five-number top line
Most conventional double-zero wagers carry about a 5.26% house edge, but the five-number wager covering 0, 00, 1, 2, and 3 is a notable exception.
It covers five of 38 pockets and commonly pays 6:1. Its expected value is:
EV = (5/38 × 6) - (33/38 × 1)
EV = -3/38 ≈ -7.89%
That makes it substantially more expensive than the ordinary double-zero straight, split, street, corner, six-line, dozen, column, or even-money wager.
This is why “all roulette bets have the same edge” is only a useful shorthand for the standard wager family, not a universal law. Side bets, bonus products, altered straight-up payouts, top-line bets, and proprietary variants must be priced from their actual rules.
See zero, double zero, and top-line bets for the green-pocket comparison.
Derive any ordinary roulette bet in three steps
You do not need to memorize every percentage if you can reconstruct it.
Step 1: Count winning pockets. A split covers 2, a street 3, a corner 4, a six-line 6, a dozen 12, and an even-money bet 18.
Step 2: Choose the wheel denominator. Use 37 for a conventional single-zero wheel and 38 for a conventional double-zero wheel.
Step 3: compare the hit probability with the payout. A fair payout would fully compensate for the losing outcomes. The casino paytable pays slightly less than true odds, creating the edge.
Example: a single-zero corner covers 4 pockets.
P(win) = 4 / 37 = 10.8108%
There are 33 losing pockets. Fair net odds would be 33:4, or 8.25:1. The conventional payout is 8:1. That small payout shortfall produces the 2.70% house edge.
This method is more durable than memorizing isolated percentages because it also helps you audit unfamiliar paytables.
Convert roulette odds into expected session cost
Probability answers “how often does this event occur?” Expected loss answers “what is the long-run cost of the action I am putting through the game?”
For a standard wager:
Expected loss = total amount wagered × house edge
Suppose two players each put $1,000 of total action through roulette:
| Game | Example edge | Expected loss on $1,000 action |
|---|---|---|
| Single-zero standard wager | 2.70% | About $27.00 |
| Double-zero standard wager | 5.26% | About $52.60 |
| Protected French even-money | ~1.35% | About $13.50 |
This is not a prediction of a particular session result. One player may win hundreds while another loses quickly. It is the long-run price attached to the same amount of action.
If you want to test stake size and spin volume, use the roulette odds calculator, expected loss calculator, or house edge calculator. For the distribution of short-run results, move to the Roulette Variance Simulator Guide.
Use this page as a probability reference, not a betting-system promise
Roulette odds do not improve because red appeared five times, because a number is marked “hot,” because you doubled after a loss, or because you stop after reaching a target. Those choices can change stake size, session length, and volatility, but they do not change the physical pocket count on an ordinary independent spin.
The useful discipline is simpler: identify the wheel, identify the wager, count the winning pockets, check the payout, and then decide whether the resulting price is acceptable to you. For a compact lookup table, continue to Roulette Odds Chart. For the terminology behind these bet names, use the Roulette Glossary.