This spreadsheet allows you build unit most efficient with the mass and power on offer


KEY:
RPS is how much resources you get from one mass extract or power generator
How many is how many of them you have
Eco is how much you will be resources per sec

R needed is resources needed
Per second is how many rescores per second you need to build one unit
How many you can build is how many factories you can have building units efficiently
Time in min is for you to set to see how many units you will get per minuet
How many you can build per what min was set

Link: http://www.gamefront.com/files/20110427/Supcom_2_help_sheet_xlsx

You need Excel 2003 or 07 or 10
You can aslo use open office