Calculate Power Consumption of 40 PCs of same build

We have a school computer lab with 40 PCs. All these PCs have same specs:


  • Lenovo H530
  • Intel® Pentium™ G3220 (3.00 GHz Dual-Core) processor
  • 2 GB RAM
  • 500 GB HDD (7200 rpm)
  • 15.6 inch TFT
  • Standard Mouse and Keyboard

more detailed specs:

How much is the power consumption of one PC?

I need to install an Online UPS for the lab and don’t know if I should go for a 6KVa UPS or a more expensive 10KVa UPS. Any help would be appreciated.