Honestly, just use the formulae in NFPA 13 and program a MS Excel sheet yourself. It is really easy. And it will teach you better how to perform the calculations.
I can dig up a spreadsheet for doing sprinkler system calcs if you are unable to program it in Excel. Just shoot me an email if you need one.
This is just a sample sheet. Configure it account for your requirements. This will give you the basis of how I made a spreadsheet awhile back for a school project.
I was reading the referenced thread from the OP and the term standpipe was being used for sprinkler protection. The term standpipe is usually referred for supplying water to hose connections at various levels of a building. By contrast the term riser is usually associated with piping system supplying water the sprinkler system. So are we looking at sprinkler protection or hose connections?
The reference from original thread is in reference to the hose connections [standpipe calc.], the spreadsheet which TravisMack attached can be modified for a standpipe calc.