As a safety measure, manufacturers of computers and other devices overstate how much amps, VA or watts their devices require. The maximum capacity is overstated, even if those devices rarely, if ever reach that capacity. Manufacturers may build in additional overhead and add capacity to this figure just to be on the safe side. Unfortunately, since manufacturers' policies vary so widely, there's no clear formula to determine a device's actual power rating. The best place to find the actual power rating of any given device is to turn to Tripp Lite for help. Use the Online Selector or call the UPS System Specialists.