How to size a UPS

You have decided that you need a UPS. What is next? How do you know which one to pick? At Eaton we are experts in sizing the right uninterruptible power supply for the job. Here are several options and tools available to assist in sizing the right UPS.

  • Use the Eaton UPS Selector tool. Our tool will walk you through a step-by-step process and display UPS options that will fit your requirements.
  • Call us! 800-356-5794. We are here to help and our experts can provide you with the right UPS choices.
  • There’s an App for that. Eaton’s UPS Tool for iPhone®, iPad® and iPod touch® helps you find the best UPS solution without being tied to your desk: and it’s free in the app store.
  • Do it the old fashioned way! With a few simple questions and calculations, you can identify your power needs and find the right Eaton UPS. Follow these steps below. Our UPS Sizing Worksheet will help you get the job done right.
    1. List all equipment to be protected by the UPS.(Remember to include monitors, external hard drives, routers, etc.)
    2. List the amps and volts for each device. These ratings can typically be found on the label on the back of the equipment. Multiply amps by volts to determine VoltAmps (VA). Some devices may list their power requirements in watts. To convert watts to VA, divide the watts by power factor. For servers, the power factor is often 0.9.
    3. Multiply the VA by the number of pieces of equipment to get the VA subtotals.
    4. Add the VA subtotals together.
    5. Multiply the total by 1.2 to get the grand total. This step accounts for future expansion.
    6. Use the grand total to select a UPS. When choosing a UPS, be sure that the total VA requirement of supported equipment does not exceed the VA rating of the UPS.
UPS Selector

UPS Sizing Worksheet

How to size a UPS

Eaton has you covered when it comes to choosing a power protection system. Here is some information to help you make the right decisions when it comes to protecting your vital IT equipment.

How to size a UPS
Print the UPS size and cost worksheets