@gcvsa@mstdn.plus @kev@social.catastrophic.horse +1 The "family" answer I give is generally the same. For a desktop PC and Monitor, something that is "at least" 800VA/500W. From that point, go with as much as you can comfortably afford. Both APC and Cyberpower are good brands with easily replaceable batteries. If you buy one with a USB cable, plug it into the PC and run the software setup. This will tell the PC to shut down when the battery runs out.