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PoE Power Budget Calculator

Check whether a PoE switch's power budget can support all connected devices.

Inputs

Typical IP camera draws 5-12W; PTZ cameras and Wi-Fi APs can draw more.

Saved Scenarios

— select 2+ to compare

Remaining Budget (W)

50.0

Total Power Draw (W)

70.0

Spark says

How it's calculated

Formula

Remaining=Switch Budget−(Devices×Watts per Device)Remaining = Switch\ Budget - (Devices \times Watts\ per\ Device)
Switch\ Budget
— The switch's total PoE power budget, from its datasheet

What is the PoE Power Budget Calculator?

A PoE switch's total power budget is shared across all connected devices — this calculator checks whether your device count and per-device draw fit within that budget, with headroom to spare.

How to use it

  1. 1 Enter your switch's total PoE power budget (from its datasheet — not the per-port maximum).
  2. 2 Enter how many PoE devices are connected.
  3. 3 Enter the typical power draw per device.

Worked examples

120W switch, 10 devices at 7W each

70W drawn, 50W remaining.

Try it

Limitations

  • •Uses each device's nameplate/typical power draw — actual draw can spike briefly above the rated figure (e.g. PTZ cameras during movement).

Frequently asked questions

What happens if I exceed the switch's PoE budget?

Most managed switches will refuse to power additional ports once the budget is exhausted, prioritizing by port order or configured priority — devices simply won't power on.