How to size a UPS
You have decided that you need a UPS. What’s next? Well, you have to pick the right one!
Alternative #1:
Visit Eaton.com/UPSselector
Alternative #2:
Do it the old fashioned way. Completing these steps is also very useful for the first two alternatives.
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 Sizing Worksheet
Product List

- PC, Workstation & Home AV UPS
- Eaton 3S (550-700 VA)
- Eaton Ellipse ECO (500-1600VA)
- Eaton 5E (500-2000VA)
- Eaton 5S (550 - 1500VA)
- Network & Server
- Eaton 5P (650-1550 VA)
- Eaton 5130 (1250-3000 VA)
- Eaton 5PX (1500-3000 VA)
- Eaton 9130 (700-6000 VA)
- Eaton 9130 RM (1000-3000 VA)
- Eaton EX (700-3000 VA)
- E Series DX (1-3 kVA)
- Eaton 9SX (5-6 kVA)
- Eaton 9PX (1-3 kVA)
- Eaton 9PX (5-11 kVA)
- Eaton 9E (6-20 kVA)
- Eaton MX (4-20 kVA)
- Eaton 9155 (8-30 KVA)
- Data Center & Facility UPS
- BladeUPS (12-60 kW)
- E Series DX ( 20-40 kVA)
- Eaton 9355 (8-40 kVA)
- Eaton 93E (15-500 kVA)
- Eaton 93PM (30-200 kW)
- Eaton 93PR (25-200 kW)
- Eaton 9390 (40-160 kVA)
- Power Xpert 9395 (225-1100 kVA)
- Marine & Offshore UPS
- Eaton 9130 Marine (1000-3000 VA)
- Eaton 9PX Marine (1500-3000 VA)
- Eaton EX Marine (1500-3000 VA)
- Eaton 9155 Marine (8-30 kVA)
- Eaton 9355 Marine (8-40 kVA)
- Power Xpert 9395 Marine (225-1100 kVA)
- DC Power