Classically, I've read coax data sheets and transcribed the information into an Excel spreadsheet to do cable loss calculations based upon frequency, cable length and cable type.

Recently, I discovered this online tool for Messi & Paoloni coax:

I've had pretty good results with their coax over the last couple of years (and I really like the design of their cable end connectors), so when the time came to purchase some new coax for a special project (multiple frequency use ranging from 3.5 MHz all the way up to 2.4 GHz) I used the above mentioned tool to pick the right coax for me.

This sounds a bit like and ad, but really it isn't. It was just nice to see something other than the usual spec sheet.

Maybe this tool is of some use to you,