Assuming starting prop is one recommended by engine manufacturer is there a table or simple method to decide on alternate prop selections?

Something that would explain or recommend alternate prop selections based on engine load and rpm.

I.E. If you use a 11/7 prop then could you select a 12/6 as a larger prop with about the same engine load? Could you use a 13/6 if you had ground clearance and get similar results?

Is their a formula to equate diameter and pitch to performance?
Something like size times pitch. I.E. 11/7 (77) is close to 10/8 (80). 11/7 (77) is very close to 13/6 (78).

The general rule of thumb isn't so scientific. One inch up in diameter and one inch down in pitch, and vice versa. The engine manufacturers give you a reasonable starting point in their recommendations, but the best prop for your particular flying style/airplane/engine is found with a bit of experimentation. Buy some different props (not just size, but brand too) and see which you think flys best.

here is a good prop chart

Thanks for the info.

I located the web site with the chart adrian attached in his reply.

http://www.top-flite.com/accys/topq5000a.html