Standard deviation in roullet

[Stefan_K]

I'm not posting this because i think that i will win in roulet, I'm just going to play. thinking about playing with 5$ and just put them on either red or black. After my calculations i will lose 13cent ((18/37)*5) per game, but what i do not know is how to calculate how big my standard deviation will be?

And also how big swings will this lead to?