I am going to make a california king rag quilt and could use some help on figuring out how many 9 1/2 inch blocks I would need.

How big do you plan to make it?

Check out this website link it has for 10" squares. It might help. Wow it says 338 squares. I would never finish it.
http://jubileehomespun.com/info/Quilt_Instructions.htm

Try this website:

http://www.dimensionsguide.com/dimen...f-a-rag-quilt/

I think once you know the right measurements, and you decide how big you will be making your squares, you will be able to figure out how many squares you will need.

Heres a link to a chart that does all the figures for you.

http://quilt.com/HowTo/YardagePage.html

Awesome Link! I don't think it will help with a rag quilt though, because it doesn't allow for the extra large seams. They are calculating with 1/4" seams.