American vs. European roulette: what the extra zero changes
Compare the 37-pocket European wheel with the 38-pocket American one, including payouts, win chances and the house edge on common bets.
At first glance, American and European roulette look nearly identical: a spinning wheel, a ball, a felt layout with numbers and colors. But one small difference changes the math in a meaningful way. This article compares the two versions, walks through the odds for common bets, and shows how to calculate the house edge yourself. It is educational, for adults 18 and over, and not an invitation to gamble. Gambling laws vary by country and U.S. state.
The wheel layouts
A European wheel has 37 pockets: the numbers 1 through 36 plus a single green zero. An American wheel has 38 pockets, adding a second green pocket marked 00. In both versions, 18 numbers are red and 18 are black, and the green pockets belong to neither color. The extra pocket does not change the payouts, which is exactly why it matters.
Payouts on common bets
The standard payouts are the same on both wheels:
- Straight up (one number): pays 35 to 1.
- Red or black, odd or even, high or low: pays 1 to 1.
- Dozens and columns: pay 2 to 1.
Because the payouts stay the same while the American wheel has an extra losing pocket, the odds are worse for the player on the American version.
Win chances compared
- Single number: 1/37, about 2.70%, on the European wheel, versus 1/38, about 2.63%, on the American wheel.
- Red: 18/37, about 48.65%, on the European wheel, versus 18/38, about 47.37%, on the American wheel.
The percentages look close, but they compound over many bets.
Calculating the house edge
The house edge is the average share of each stake the casino expects to keep over the long run. Take a straight-up bet of 1 unit.
- European: you win 35 units with probability 1/37 and lose 1 unit with probability 36/37. The average result is (35 x 1 - 1 x 36) / 37 = -1/37, a loss of about 2.70% of the stake.
- American: the same bet has an average result of (35 x 1 - 1 x 37) / 38 = -2/38, a loss of about 5.26%.
In other words, the extra pocket roughly doubles the house edge. The same percentages apply to the even-money bets, since they are built from the same wheel.
Special rules and the five-number bet
Some European-style tables apply rules such as "la partage" or "en prison," which return half of an even-money stake, or hold it for the next spin, when the ball lands on zero. Under la partage the house edge on even-money bets falls to roughly 1.35%. These rules vary by venue, so always read the table sign.
American tables offer a bet on 0, 00, 1, 2 and 3, usually paying 6 to 1. Its house edge is about 7.89%, the highest on the layout. Knowing which bets carry the worst odds is useful information for any player.
What does not change
No bet or pattern turns roulette into a winning proposition. Each spin is independent, so results on the display board tell you nothing about the next one. If you are tempted by the belief that a color is "due," see our explanation of the gambler's fallacy. For a deeper look at how payouts translate into likelihood, our guide to reading American, decimal and fractional odds is a good companion.
Responsible considerations
Because the game moves quickly, a spending limit and a time limit set in advance are essential. If you choose to play, treat the money as the cost of entertainment and stop when you reach your limit.
Frequently asked questions
Which version is better for the player?
The European wheel, since it has one fewer losing pocket and therefore a lower house edge.
Do the colors affect the odds?
No. Red and black have equal chances on each wheel. Only the green pockets tilt the game toward the house.
Is there any betting system that beats roulette?
No. Systems change the pattern of wins and losses but cannot overcome the built-in house edge.