1500VA UPS Runtime Calculator

Use this calculator to estimate the runtime of a 1500VA UPS. Just enter your equipment's wattage, and find out how long the UPS will support your devices during a power outage.

Enter the total wattage of your connected devices

List of the Best 1500VA UPS:

# Image Product Link
1 CyberPower CP1500PFCLCD PFC Sinewave UPS System, 1500VA/1000W, 12 Outlets, AVR, Mini Tower,Black CyberPower CP1500PFCLCD PFC Sinewave UPS System, 1500VA/1000W, 12 Outlets, AVR, Mini Tower,Black View on Amazon
2 APC UPS 1500VA UPS Battery Backup and Surge Protector, BX1500M Backup Battery Power Supply, AVR, Dataline Protection APC UPS 1500VA UPS Battery Backup and Surge Protector, BX1500M Backup Battery Power Supply, AVR, Dataline Protection View on Amazon
3 CyberPower CP1500AVRLCD3 Intelligent LCD UPS System, 1500VA/900W, 12 Outlets, 2 USB Ports, AVR, Mini Tower, Black CyberPower CP1500AVRLCD3 Intelligent LCD UPS System, 1500VA/900W, 12 Outlets, 2 USB Ports, AVR, Mini Tower, Black View on Amazon
4 Vertiv Liebert PSA5 UPS - 1500VA 900W 120V Line Interactive AVR Tower UPS, 10 outlets, 2 USB Charging Ports, Battery Backup w/ Surge Protection, 3 year warranty, Energy Star Certified(PSA5-1500MT120) Vertiv Liebert PSA5 UPS - 1500VA 900W 120V Line Interactive AVR Tower UPS, 10 outlets, 2 USB Charging Ports, Battery Backup w/ Surge Protection, 3 year warranty, Energy Star Certified(PSA5-1500MT120) View on Amazon
5 Tripp Lite SMART1500LCD 1500VA Rack Mount UPS Battery Backup, 900W, 8 Outlets, PWM Sine Wave, Short Depth 2U Rackmount UPS, AVR, LCD Screen Tripp Lite SMART1500LCD 1500VA Rack Mount UPS Battery Backup, 900W, 8 Outlets, PWM Sine Wave, Short Depth 2U Rackmount UPS, AVR, LCD Screen View on Amazon

1500VA UPS Runtime Explained

A 1500VA UPS is one of the most common sizes for home offices and small business setups. It provides backup power during outages, allowing safe shutdown of computers, routers, NAS devices, and other sensitive electronics.

How Runtime is Estimated

This calculator assumes the following typical parameters:

  • Power Factor: 0.7 (real output = 1050W)
  • UPS Efficiency: 85%
  • Base Runtime: 5 minutes at full load (approximate)

Runtime increases significantly at lower loads. For example, using only 400W of a 1500VA UPS might yield 15+ minutes of runtime, depending on battery condition and temperature.

Typical Applications for 1500VA UPS

  • 1–2 desktop computers with monitors
  • Small NAS or server
  • Router/modem and networking gear
  • POS systems and control panels

Frequently Asked Questions

What happens if I exceed 1500VA or 1050W?

The UPS may shut down or instantly switch to bypass. Overloading can damage the battery or inverter.

Is the runtime fixed?

No. Runtime varies by battery age, temperature, and actual load. This calculator gives a close estimate for planning purposes.

Can I add external batteries?

Some higher-end models like APC SMT1500 allow external battery packs to extend runtime.