Roulette odds explained: payouts and probabilities

Win probability tells you how often a particular bet succeeds in the mathematical model. House edge measures its average loss as a share of money wagered. A bet can win more often than another bet while keeping the same house edge.

House edge and RTP

On standard European red, a $1 stake wins $1 on 18 pockets and loses $1 on 19. The expected net result is (18 × $1 − 19 × $1) ÷ 37 = −$1/37, about −$0.027 per dollar wagered. That gives a house edge of 2.70% and a theoretical return to player, or RTP, of 97.30%.

A straight-up bet has a much lower hit rate but the same edge under the standard European paytable. Its larger payout compensates for much of the difference in winning frequency. It does not remove the gap between the true odds and the payout.

Evolution’s French Roulette description confirms the La Partage half-loss rule for even-money bets. It changes what happens on zero; the probability of a red win remains 18/37. The 1.35% edge does not apply to dozens, columns, or inside bets. Our French Roulette La Partage guide explains the eligible bets.

RTP is an average under the rules over many wagers. It is not a promise that a $100 deposit will return $97.30. Total wagering can exceed the initial deposit when money is staked again. At a 2.70% edge, $1,000 in total standard European wagers has an expected loss of about $27.03 using the unrounded rate. An individual session can end far above or below that average.

The UK Gambling Commission’s RTP and house-edge explanation describes the house edge as the average share of stakes the casino expects to retain. For a deeper treatment of expected value and betting systems, see our mathematical roulette strategy analysis.

Combined bets: a winning chip versus a profitable round

When bets overlap, count each winning pocket once to find the chance of receiving any payout. Then calculate the money returned on each possible outcome to find the chance of a net profit. Adding the separate probabilities can count the same pocket twice.

Consider $1 on red and $1 on the first dozen on a standard European wheel. The total stake is $2. Six numbers in the first dozen are red, so the covered sets overlap on six pockets.

At least one bet wins on 18 + 12 − 6 = 24 pockets, a probability of 24/37 or 64.86%. The round makes a net profit on 12 pockets, or 32.43%. It breaks even on another 12 and loses on 13. The combined stake still carries the standard 2.70% house edge.

Equal bets on red and black give another useful example. With $1 on each, any red or black result returns $2 against a $2 total stake, leaving no profit. Zero loses both wagers under standard full-loss rules. Covering 36 pockets gives a high chance of breaking even and no chance of a profitable round.

Our roulette odds calculator provides an interactive betting layout. When interpreting a combined-bet result, distinguish the chance of any winning wager from the chance that the total return exceeds the whole stake.

What changes across several spins?

On an independent European spin, a chosen number always has probability 1/37. Missing for 20 spins does not raise its chance on the next spin. A recent hit does not lower it either.

The probability of seeing that same, preselected number at least once across several spins is a different question. For n independent European spins, it is 1 − (36/37)ⁿ. This subtracts the chance of missing on every spin from 1.

The expected number of hits over 37 spins is one, but the actual count can be zero, one, or several. A hit within the sequence also does not guarantee a profit from betting on every spin. For example, 37 separate $1 straight-up wagers cost $37; exactly one win returns $36, leaving a $1 loss.

Using the figures before placing a bet

Check the number of zero pockets, the actual payout, any fee, and the zero-settlement rule. Decide what you are measuring: a single bet winning, any wager paying, or a net profit after all stakes. Keep the total amount wagered and the number of rounds within limits you can afford to lose. Increasing stakes after losses does not change the next spin’s probability.

Our live roulette strategy guide covers table selection and session limits. If you use our live casino comparisons, check access and the rules at the operator. Any roulette bonus has separate eligibility, game-contribution, and wagering terms; it does not change the wheel’s probabilities.

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Roulette odds FAQ

What are the odds of winning in roulette?

They depend on the bet and wheel. A straight-up bet wins with probability 1/37, or 2.70%, on a European wheel and 1/38, or 2.63%, on an American wheel. Red and black each win with probability 18/37, or 48.65%, and 18/38, or 47.37%, respectively. Those are single-bet probabilities, not a prediction of session profit.

Is betting on red or black a 50/50 chance?

No. A European wheel has 18 red, 18 black, and one green zero. An American wheel adds a second green pocket, 00. The zeros prevent red and black from each having a 50% chance. Under standard full-loss rules, the house edge is 2.70% on single zero and 5.26% on double zero.

Does a 35:1 payout include the original stake?

A standard 35:1 payout means 35 units of profit for each unit wagered, plus the return of the winning stake. A $1 winning straight-up bet returns $36 in total. Subtract any other stakes lost in the round to calculate the net result.

Which roulette bet has the highest chance of winning?

Among the individual standard bets in these charts, red, black, odd, even, low (1–18), and high (19–36) each cover 18 pockets and have the highest win probability. Their standard payout is 1:1. Frequent payouts do not make a wager safe or remove its house edge.

Do earlier spins change the next roulette result?

Under the fair, independent-spin model, they do not. A number that has missed repeatedly retains the same probability on the next spin. Results histories show what happened earlier; a streak does not make an opposite result due.

Why does La Partage have a lower house edge?

On a single-zero table with La Partage, an eligible even-money bet loses only half its stake when zero wins. The probability of an ordinary winning result stays the same, but the smaller loss on zero reduces the house edge to about 1.35%. Inside bets, dozens, and columns do not receive that half return.