Free tools › PoE switch budget
Will your PoE switch power everything at night?
A PoE switch has a total power budget as well as a number of ports. Add the cameras, access points, readers and intercoms on it and check the watts, the ports and the PoE standard each one needs.
The switch
On the datasheet as "PoE budget" or "PoE power". Not the same as the power supply rating.
What is plugged in
| Load | Watts | Against the budget |
|---|
Method: the device watts are added up and held against the switch's PoE budget, with at least 20% kept spare. Two harder checks follow. The first adds the cable loss the PoE standard allows on a 100 m run: PoE 2.45 W, PoE+ 4.5 W, PoE++ 9 W or 18.7 W per port. The second adds the full class power, for a switch that reserves each port's class maximum (class 3 is 15.4 W, class 4 is 30 W). Defaults per device type are typical figures; use the datasheet's maximum.