Typically, that the UPS (The Uninterruptible Power Supply), or backup power sold to the current GPS power unit.
VA as 600VA 700VA 800VA 1000VA (or 1kVA) up to several sizes up to 900KVA it.
We can calculate the Watt from the VA, we need to know the Power Factor (PF) of each predecessor. UPS is used
According to a House of Line Interactive with Stabilizer typically a Power Factor (PF) is 0.6, so let’s say a UPS type.
Line Interactive with Stabilizer Capacity 1000VA (1kVA) We can not calculate.
1000(VA) X 0.6 = 600 (Watt)
This UPS can support the load that the UPS is up to 600Watt type True On-Line, has the power factor is.
Approximately 0.7-0.8 depending on the circuit can be designed more information, contact the company that sold the product.