Green roulette odds: zero and double zero

One specific zero

A straight-up on 0 has a 1/37 chance on European roulette, 1/38 on American roulette and 1/39 on triple zero. A straight-up on 00 is a separate ticket and is only available when that pocket exists.

The chance of any green

Any green occurs with probability 1/37, 2/38 or 3/39 on the three wheel types. That is 2.70%, 5.26% and 7.69%. These are event probabilities, not the payout for a universal green button.

Green does not automatically pay more

A standard straight-up zero pays 35:1, just like another single number. Covering both 0 and 00 with two equal straight-up bets doubles the total stake. If either wins, one ticket wins and the other loses.

Two zero bets on an American wheel

Place a hypothetical $1 on 0 and $1 on 00. Either zero returns $36 total, for $34 net profit after both stakes. Any other number loses $2. The chance of positive profit is 2/38, or 5.26%.

Odds of hitting green by wheel

How often does green come up?

On a European wheel zero is expected once every 37 spins on average, but it is not due after 37 spins. The chance of no zero at all in 37 spins is 36.29%, so at least one zero appears in 63.71% of 37-spin blocks. On an American wheel the chance of at least one 0 or 00 in 38 spins is 87.19%.

Each spin stays independent. A long gap since the last zero does not raise the chance of green on the next spin.

The odds of 0 and 00 on an American wheel

A straight-up bet on 00 wins with probability 1/38, or 2.63%, the same as 0 or any other single number. The 0-00 split covers both at 17:1 and wins 2/38 of the time. The first-five basket adds 1, 2 and 3 at 6:1 and has a higher 7.89% house edge.