The count depends on which wheel is in front of you
A player walking up to a roulette table usually sees a wheel with red and black pockets alternating around the outside and a green pocket, or two, breaking the pattern. The number of black pockets is not something the casino adjusts from day to day. It is fixed by the wheel's construction, and it differs between the two common layouts.
On a European-style wheel there are 37 pockets in total: the numbers 1 through 36 plus a single zero. Half of the numbered pockets are black, so the wheel carries 18 black pockets and 18 red pockets, with the zero in green. An American-style wheel has 38 pockets because it adds a double zero alongside the single zero. The numbered section is unchanged, so that wheel also has 18 black pockets and 18 red pockets, with the two zeros both green.
What changes between the two wheels is not the count of black numbers but the number of green pockets. The extra zero on the American layout is the reason the house edge on most bets is higher there, even though a bet on black still covers 18 pockets on either wheel.
Which numbers are black, and how they sit on the wheel
The black numbers are not the same as the even numbers, and they are not arranged in a simple alternating sequence around the wheel. On both common layouts the black numbers are 2, 4, 6, 8, 10, 11, 13, 15, 17, 20, 22, 24, 26, 28, 29, 31, 33 and 35. The red numbers are the remaining 18 numbers from 1 to 36.
A common misreading is to assume the wheel alternates red and black one-for-one all the way around. It does not. The wheel is arranged so that red and black alternate for stretches, but the sequence is interrupted so that no simple half of the wheel is all one color. The arrangement is a design choice meant to spread high and low numbers, odd and even numbers, and the two colors around the wheel rather than clustering them.
The betting layout on the table is a different thing from the wheel itself. The layout arranges the numbers in three columns and twelve rows, and the colors on the layout follow the same assignment as the wheel. A player betting on black is not betting on a section of the wheel; they are betting on the 18 numbers that carry the black color, wherever those numbers sit on the wheel.
What a bet on black pays
A bet on black is one of the even-money bets, also called outside bets because they sit on the outer part of the table layout. The other even-money bets are red, odd, even, low and high. An even-money bet pays 1 to 1: a winning bet returns the stake plus an equal amount in profit.
The payout is the same on both wheel types, but the chance of winning is not. The comparison below shows why the extra zero changes the arithmetic even though the payout does not move.
| Wheel type | Total pockets | Black pockets | Payout on black | Why the edge differs |
|---|---|---|---|---|
| European | 37 | 18 | 1 to 1 | One green zero sits outside the bet, so the bet covers 18 of 37 pockets |
| American | 38 | 18 | 1 to 1 | Two green zeros sit outside the bet, so the bet covers 18 of 38 pockets |
The house edge on a bet is the share of each wager the operator expects to keep over a very large number of spins. On a European wheel, a bet on black loses when the zero appears and wins on 18 of the 37 pockets, which produces a lower edge than the same bet on an American wheel, where the two zeros both defeat the bet. The difference is not in the number of black pockets; it is entirely in the number of green pockets that sit outside every even-money bet.
Inside bets, outside bets, and where black fits
Roulette bets split into two families. Outside bets cover large groups of numbers and pay at lower odds: red or black, odd or even, low or high, dozens and columns. Inside bets sit on the numbered grid and cover single numbers or small groups, paying at higher odds because they win less often.
A bet on black is an outside bet and carries one of the lowest house edges on the table, but that does not make it a winning bet. It changes the rate of expected loss compared with riskier inside bets, not the direction of the result. Over any short session the outcome is dominated by variance: the wheel can land on black many times in a row or miss it for a long stretch, and neither pattern changes what the next spin will do.
The table below compares the main bet families a new player will see, with the edge described structurally rather than as a fixed percentage, since the exact figure depends on the wheel type and the specific bet.
| Bet family | What it covers | Typical payout | How the edge behaves |
|---|---|---|---|
| Even-money outside bets | 18 numbers by color, parity or range | 1 to 1 | Lower edge; the zero or zeros defeat the bet |
| Dozens and columns | 12 numbers | 2 to 1 | Higher edge than even-money bets on the same wheel |
| Inside bets | 1 to 6 numbers depending on placement | Varies, up to 35 to 1 for a straight-up number | Highest edge; the payout is below what the true odds would require |
The important point for a new player is that the edge is not uniform across the table. Two bets on the same wheel can carry materially different expected loss rates, and the player's only real choices are which bet to make, how much to stake, and how long to stay at the table.
The sequence of a round, from buy-in to settlement
Knowing the wheel layout is one part of sitting down correctly. The procedural side matters just as much, because most mistakes at a roulette table are not about the colors but about how and when money and chips move.
A player buys in at the table with cash or a casino account balance and receives roulette chips. On many tables these chips have no denomination printed on them and are used only at that table; they must be cashed out before leaving. The dealer sets a value per chip, and the player's stack is worth that value times the number of chips.
Bets are placed on the layout before the dealer calls for no more bets. Once the ball is in motion, the layout is closed. A player who tries to add or move chips after the call will have the action corrected or the bet returned, depending on the house procedure. When the ball settles, the dealer marks the winning number, clears losing bets, and pays winners from the outside inward. The player then leaves winning bets in place or removes them, and the next round begins.
The two procedural mistakes new players make most often are leaving the table with table chips still in hand and trying to touch a bet after the no-more-bets call. Table chips cannot be redeemed at the cashier; they must be exchanged for value chips at the table first. And a late hand on the layout will be treated as a late bet, not as a harmless adjustment.
What the colors do not tell you
The color of a pocket carries no information about what will happen next. A wheel that has landed on black five times in a row is not more or less likely to land on black again. Each spin is an independent event, and the wheel has no memory. The black pockets are a fixed set of 18 numbers, and the only thing that changes from spin to spin is where the ball stops.
Roulette is a negative-expectation game on every bet. The house edge is built into the payout schedule and the presence of the zero or zeros, and no bet selection removes it. A player can choose a bet with a lower edge, play fewer spins per hour, or set a stop limit, and those choices change the expected rate of loss. They do not turn the game into a source of profit.
FAQ
Are there 18 black numbers on every roulette wheel?
Yes. Both the European and American layouts use the same 18 black numbers from 1 to 36. The difference between the wheels is in the green zeros, not in the count of black or red pockets.
Does betting on black pay more on an American wheel because there are two zeros?
No. The payout stays at 1 to 1. The extra zero means the bet wins less often, so the expected loss on that bet is higher on an American wheel even though the payout is identical.
Why does the zero defeat a bet on black?
The zero is green, so it is not covered by a bet on black, red, odd, even, low or high. When the ball lands in a zero pocket, every even-money outside bet loses, which is how the house edge is built into those bets.
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This article is general information about how these mechanics work. It is not legal advice and not a recommendation to gamble or to use any particular operator. Availability and legality differ by jurisdiction — check the rules that apply where you are.