Do some googling and you'll discover that you need the individual power ratings for each of those equipment, in Watts. You can get the total of that, and head to the Internet again for those calculators used to size a UPS. There are some factors used in the sizing calculation. Most importantly would be how long you'd want to have the equipment running in case there is power failure... Looking at all those equipment,I suggest you talk to Chloride Exide or any other reputable company that does Inverters .... Be meticulous when doing the calculation, unless you have compromises to make.