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A UPS keeps the essentials running through load-shedding — but only if it is sized correctly for your load and backup needs. This Inverter Runtime Calculator sizes a UPS system from the appliances you need to power and the backup hours you want.

The calculation combines the load wattage and the desired backup time to arrive at the battery capacity and UPS rating required, using the standard relationship between watts, battery volts and amp-hours.

The most common UPS mistake in Pakistan is buying on the VA rating without checking the battery: two 'same size' UPS units can differ hugely in backup time because battery capacity varies. This tool sizes the battery, which is what actually determines runtime.

Remember the 50% rule for lead-acid batteries: plan for discharge down to about half capacity to protect battery life. The calculator's result reflects usable capacity, so the backup time it shows is realistic.

A UPS keeps the essentials running through load-shedding — but only if it is sized correctly for your load and backup needs. This UPS Size Calculator sizes a UPS system from the appliances you need to power and the backup hours you want.

The calculation combines the load wattage and the desired backup time to arrive at the battery capacity and UPS rating required, using the standard relationship between watts, battery volts and amp-hours.

The most common UPS mistake in Pakistan is buying on the VA rating without checking the battery: two 'same size' UPS units can differ hugely in backup time because battery capacity varies. This tool sizes the battery, which is what actually determines runtime.

Remember the 50% rule for lead-acid batteries: plan for discharge down to about half capacity to protect battery life. The calculator's result reflects usable capacity, so the backup time it shows is realistic.