UPS Runtime Calculator
Estimate how long a UPS will keep your equipment running during a power outage, or how large a battery you need for the runtime you want.
Equipment on the UPS
Watts are typical figures. For a firm number, use the wattage on each device's label, or a plug-in power meter. A PoE switch also powers every camera, phone and access point plugged into it, so include that load in its watts.
Battery and UPS
The UPS rating is printed on the unit, for example 1500VA / 900W. Not sure about a unit? Use the other tools for speeds, transfer times and subnets.
Estimate
| Load | Watts | Runtime |
|---|
This is an estimate. It starts from the battery's rated capacity, then allows for battery age, the share of the battery a UPS can actually use, inverter losses, and the fact that batteries deliver less capacity when drained quickly. Real runtime also varies with temperature and the exact UPS model, so check the manufacturer's runtime chart before you rely on a number.