Help me calculate my compression ratio!

[nick_94cobra]

I was wondering what was the best way to go about calculating my compression ratio. i'm running a eagle 331 stroker kit, peformer rpm heads, peformer rpm intake. the stroker kit is exactly how it left the box, but i milled 40 thousands off the pistons to get them to fit. i believe the compression started at 9.5:1 with the kit, but i'm not sure. is there a easy way to figure this out?

 

[88mouse]

try this

http://www.csgnetwork.com/compcalc.html