UPS Load Calculator
What can your UPS run during load shedding?
About this calculator
Load shedding still hits many parts of Pakistan, and a UPS only helps if the load matches what it can handle. This calculator lets you add up the appliances you want to run — fans, lights, LED TV, Wi-Fi router, laptop — in watts, then shows whether a given UPS capacity can carry them and for roughly how long.
It estimates backup time from your battery size (in AH) and inverter efficiency, and flags when your planned load is too heavy for the setup. That saves you from the classic mistake of buying a UPS that dies twenty minutes into an outage — or overspending on a system far bigger than your needs.
How to use
- Add each appliance you want on backup and enter its wattage.
- Enter your UPS inverter capacity and battery size in AH.
- See whether the load fits and the estimated backup hours.
- Adjust the appliance list until the backup time covers your usual outage.
Frequently asked questions
How much wattage does a ceiling fan use?
A standard Pakistani ceiling fan uses about 70–80 watts. Energy-saver (inverter) fans use roughly 30–35 watts, which is why many people switch to them for UPS backup.
How is backup time estimated?
Roughly: battery volts × amp-hours × inverter efficiency ÷ total load watts. A 100 AH, 12 V battery at 80% efficiency with a 300 W load gives about 3 hours — the tool does this maths for you.
Can a UPS run an air conditioner?
Normally no. Even a 1-ton inverter AC draws around 1,000 watts or more at startup, which is far beyond a typical home UPS. ACs need a generator or a large solar setup instead.
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