UPS Sizing Calculator
Add your equipment below to calculate the UPS size you need. We factor in a 0.6 power factor and recommend a unit with enough headroom to keep your gear protected without overloading the battery.
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Understanding the Numbers
Power Factor (0.6)
UPS units are rated in VA (volt-amperes), but your equipment consumes real power in watts. The ratio between the two is the power factor. Most UPS units operate at a 0.6 power factor, meaning a 1000VA UPS delivers around 600W of usable power. We use this ratio to convert your wattage into the correct VA requirement.
Headroom
Never run a UPS at 100% capacity. We recommend keeping your load at 60-70% of the UPS rated capacity. This extends battery life, reduces heat, and gives you room to add devices later. The calculator picks the next standard VA size above your requirement to ensure adequate headroom.
Runtime Estimates
Runtime depends on battery size and your actual load. The estimates here assume typical battery configurations for each VA class at the calculated load. Real-world runtime varies by manufacturer and model. Check the specific product's runtime chart for precise figures.
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