07/23/2017 UPDATE:
Updated Port Flow Calculator. When using the Intake Initial Flow and Exhaust Initial Flow, the Intake/Exhaust ratio was not being calculated. That has been fixed.
A Windows version will be coming within the next month.
NOTES:
I recommend running Linux Mint. If you have a 32-bit computer (meaning..something very old) then get the 32 bit version, otherwise get the 64-bit version. Cinnamon Desktop is what I recommend.
MINIMUM System Requirements:
Linux with SQLite3 installed.
Minimum screen resolution is 1304×718.
As far as a printer, I used a HP Deskjet 970cxi, plugged in via USB.
Download Port Flow Calculator version 1 here.
Installing Linux Mint 17 and running Port Flow Calculator.
Using Port Flow Calculator.