There are a number of previous forum posts about it.
Here are just a couple:
https://www.wgt.com/forums/t/105102.aspx
https://www.wgt.com/forums/p/57783/4365445.aspx
And this one links to an actual calculator, apparently (I haven't tried it)
https://www.wgt.com/forums/p/427072/3325952.aspx