It doesn't matter how you bet. The payoff odds on an American roulette wheel are 35 to 1, as though there are only 36 slots and there is a 1 chance in 36 of hitting your number. But, there are actually 38 slots on the wheel, 1 thru 36, plus 0 and 00.
In a standard game of roulette, there are 38 numbered pockets on the wheel: 1 through 36, plus a 0 and a 00. The odds of hitting any particular number, including 0 or 00, are 1 in 38, or approximately 2.63%. This means that, on average, a player can expect to hit 0 or 00 once every 38 spins of the wheel.