The house edge on roulette depends almost entirely on how many zero pockets the wheel has. A single-zero wheel (37 pockets) has an edge of 2.70%, a double-zero wheel (38 pockets) 5.26%, and a triple-zero wheel (39 pockets) 7.69% — and on a given wheel, every standard bet carries the same edge.
That one fact explains most of what you need to know about roulette odds. The rest of this guide shows where the numbers come from, gives a full table for every bet, and points out the one bet on the double-zero wheel that is worse than the rest.
Where the house edge comes from
Roulette payouts are set as if the zeros didn't exist. A straight-up bet on one number pays 35 to 1. If the wheel had only the 36 numbered pockets, that would be a perfectly fair price: you would win once in 36 spins on average, collect 35 units, and lose 35 units on the other 35 spins. Net result: zero.
The zero pocket breaks that balance. With 37 pockets you still get paid 35 to 1, but you now win only once in 37 spins. Here is the worked calculation for a 1-unit straight-up bet on a single-zero wheel:
- Chance of winning: 1/37 = 2.70%
- Chance of losing: 36/37 = 97.30%
- Expected result: (1/37 × 35) − (36/37 × 1) = 35/37 − 36/37 = −1/37
- As a percentage: −1/37 = −2.70% of every unit staked
Repeat the calculation with 38 pockets and you get −2/38 = −5.26%. With 39 pockets it's −3/39 = −7.69%. In words: the house edge is simply the number of zeros divided by the number of pockets.
Odds for every standard bet
The table below covers every standard inside and outside bet. "Win chance" is the probability that the bet wins on a single spin. "Edge" is the expected loss as a share of your stake. All figures were recomputed with a script before publishing.
| Bet | Numbers covered | Payout | Win chance (37) | Edge (37) | Win chance (38) | Edge (38) | Win chance (39) | Edge (39) |
|---|---|---|---|---|---|---|---|---|
| Straight up | 1 | 35:1 | 2.70% | 2.70% | 2.63% | 5.26% | 2.56% | 7.69% |
| Split | 2 | 17:1 | 5.41% | 2.70% | 5.26% | 5.26% | 5.13% | 7.69% |
| Street | 3 | 11:1 | 8.11% | 2.70% | 7.89% | 5.26% | 7.69% | 7.69% |
| Corner | 4 | 8:1 | 10.81% | 2.70% | 10.53% | 5.26% | 10.26% | 7.69% |
| Six line | 6 | 5:1 | 16.22% | 2.70% | 15.79% | 5.26% | 15.38% | 7.69% |
| Dozen | 12 | 2:1 | 32.43% | 2.70% | 31.58% | 5.26% | 30.77% | 7.69% |
| Column | 12 | 2:1 | 32.43% | 2.70% | 31.58% | 5.26% | 30.77% | 7.69% |
| Red / Black, Odd / Even, 1–18 / 19–36 | 18 | 1:1 | 48.65% | 2.70% | 47.37% | 5.26% | 46.15% | 7.69% |
Read across any row and you see the same pattern: the win chance drops a little with each extra zero, the payout stays put, and the edge climbs.
The exception: the five-number bet
On a double-zero wheel you can usually bet on 0, 00, 1, 2 and 3 together. It pays 6 to 1, wins 5 times in 38, and carries an edge of 7.89% — the worst standard bet on that wheel. It is the one place where the choice of bet, rather than the choice of wheel, changes the edge.
Why "safer" bets aren't cheaper
It's natural to assume that betting on red is the careful option and a single number is the reckless one. In one sense that's right: even-money bets win nearly half the time, so your balance moves in small steps. A straight-up bet loses most spins and occasionally pays a large amount, so your balance moves in jumps.
But the price you pay for playing is the same. Over many spins, both approaches lose about 2.70% of everything staked on a single-zero wheel. The bet type changes the ride, not the destination.
A useful way to see this is expected cost per 100 units staked:
| Wheel | Pockets | House edge | Expected cost per 100 units staked |
|---|---|---|---|
| Single zero | 37 | 2.70% | 2.70 units |
| Double zero | 38 | 5.26% | 5.26 units |
| Triple zero | 39 | 7.69% | 7.69 units |
"Staked" means the total of every bet you place, not your starting balance. If you bet 1 unit a spin for 300 spins, you have staked 300 units, and your expected cost on a single-zero wheel is about 8.1 units — even if you started with only 50.
A fictional session, worked through
Here is a fictional example to show how the numbers combine.
Mira has a budget of 50 units and plays a single-zero wheel. She bets 2 units on black each spin for 60 spins.
- Total staked: 2 × 60 = 120 units.
- Expected cost: 120 × 2.70% = 3.24 units.
- Expected balance at the end: 50 − 3.24 = 46.76 units.
The real result of any session will scatter widely around that figure. Mira could finish with 60 units or with 30. What the edge tells her is the average cost of the entertainment if she repeated sessions like this many times. If she switched to a double-zero wheel with the same habits, the expected cost would jump to 120 × 5.26% = 6.32 units — nearly twice as much, for the same game.
Rules that change the edge
A few table rules change the maths. Always check the game's rules or help panel before assuming any of these apply.
- La partage: on some single-zero games, if the ball lands on zero you get half of an even-money bet back. That cuts the edge on even-money bets to 1.35%.
- En prison: a similar rule that "imprisons" an even-money bet for one more spin after a zero instead of returning half. The edge works out roughly the same as la partage.
- Extra zeros or bonus pockets: any extra pocket that doesn't pay on standard bets increases the edge. Triple-zero wheels are the common example.
- Changed payouts: some digital variants pay slightly less than the classic odds (for example 34 to 1 on a single number). A one-unit cut in payout on a straight bet raises the edge significantly, so it's worth reading the pay table.
Quick checklist before you play
- Count the zeros. One zero = 2.70%, two = 5.26%, three = 7.69%.
- Check the payouts match the classic table above.
- Look for la partage or en prison if you play even-money bets.
- Avoid the five-number bet on double-zero wheels.
- Decide your budget in advance and treat it as the cost of play.
- Remember that no bet type or sequence of bets changes the edge. We test that claim in our guide to betting systems.
If you play roulette on crypto sites, you may also meet wheels that look nothing like the classic layout. Our guide to crypto and skin-site roulette variants shows how to work out their edge with the same method used here.
Questions readers ask
What is the house edge on European roulette?
2.70%, or exactly 1/37. On a single-zero wheel every standard bet, from a straight-up number to red or black, carries that same edge.
Why is American roulette worse than European roulette?
The extra double-zero pocket adds a 38th outcome without changing the payouts. That raises the edge from 2.70% to 5.26% on almost every bet.
Does betting on red instead of a single number lower the house edge?
No. Even-money bets win more often but pay less. On a given wheel the edge is the same for every standard bet; only how bumpy the results feel changes.
What is la partage?
A rule on some single-zero tables that returns half of an even-money stake when the ball lands on zero. It halves the edge on those bets to about 1.35%. Check the game rules to see if it applies.