Single-number roulette odds

One number out of the whole wheel

A chosen number wins with probability 1/37 on European roulette, 1/38 on American roulette and 1/39 on triple zero. These are about 2.70%, 2.63% and 2.56% respectively. No number has a built-in advantage.

True odds and payout odds differ

With 37 pockets there are 36 losing outcomes for one winning outcome. True odds against are 36:1, while standard net payout is 35:1. That gap produces the house edge.

The same number twice

Before two spins, the chance of a particular number appearing both times is (1/37)^2 on a European wheel. If the first result is already known and any matching second result counts, the chance of a repeat on the next spin is 1/37.

Number labels and colors

A query mentioning 11, 17, 22 or 32 still describes one pocket if a straight-up bet is meant. Choosing a number because it appeared often in a short history does not alter its next-spin probability on a fair wheel.

Single-number odds on each wheel

Chance of hitting your number within several spins

The chance of at least one hit on a chosen number across n future spins is 1 − (36/37)^n on a European wheel. Even 37 spins give no guarantee.

Straight-up payout example

A $5 straight-up bet on 17 that wins pays $175 profit, and the $5 stake is returned for $180 in total. On the other 36 European outcomes the $5 is lost. Expected net per spin is (1/37 × $175) − (36/37 × $5), or about −$0.14.