Excel based actual R value calculator

FWIW, I just made this up while thinking about the recent threads between Mike and Frenchy. I figured I would post as someone might want a non-‘net based method to calculate the wall performance.
To use, just pick a section (16″x16″ would work well with 16″ oc. studs) and enter the thickness and type of material for the given portion.
Jon Blakemore