Usually, a UPS (Uninterruptible power supply) or uninterruptible power supply that is currently on sale will tell the power rating of the unit as
VA, such as 600VA 700VA 800VA 1000VA (or 1kVA) up to many sizes up to 900KVA also
We are able to calculate Watt from the VA. We need to know the Power Factor (PF) of each model first. Like UPS that is used
In normal household type, Line Interactive with Stabilizer, the Power Factor (PF) is 0.6. So, let’s say it is UPS type.
Line Interactive with Stabilizer 1000VA (1kVA), we can calculate as
1000 (VA) X 0.6 = 600 (Watt)
Therefore, this UPS can support a maximum load of 600Watt. The True On-Line UPS will have a power factor at
Approximately 0.7-0.8, depending on the circuit designed by which can inquire at the company that sells the product