Equation to approximate percent likelyhood of different sigma events

[jaydnul]

Hi!

I was wondering if there was an equation to plug in a standard deviation value and get back approximately the percent likely hood of getting that sigma (for example 1 sigma would be 33%, 3 sigma 0.27%, etc).

Just something that approximates it with algebra, no calculus

Thanks!

 

[hutchphd]

Ought to be in this: https://en.wikipedia.org/wiki/Error_function#Approximation_with_elementary_functionsre: