PoE Budget Calculator – Will Your Switch Power Everything?

Enter how many access points, cameras and other PoE devices you have and how much power each one draws. The calculator adds up the total, applies a safety reserve and compares the result with the PoE budget of your switch – the total power it can deliver over all ports. Use the maximum power from the data sheet, not the typical value.

Formula

P = APs × W + cameras × W + other × W
required = P × (1 + reserve)
remaining = switch budget − required

Calculations run locally in your browser. Results are for information only — for engineering, electrical or financial decisions, verify the assumptions and applicable standards.

Access points (pcs): 2 · Power per AP (W): 13 · Switch PoE budget (W): 60 · Cameras (pcs): 0 · Power per camera (W): 7 · Reserve (%): 30 · Other PoE devices (pcs): 0 · Power per device (W): 6 → Total PoE draw: 26 W
Access points (pcs): 4 · Power per AP (W): 21 · Switch PoE budget (W): 150 · Cameras (pcs): 6 · Power per camera (W): 12 · Reserve (%): 30 · Other PoE devices (pcs): 0 · Power per device (W): 6 → Total PoE draw: 156 W
Access points (pcs): 1 · Power per AP (W): 13 · Switch PoE budget (W): 65 · Cameras (pcs): 8 · Power per camera (W): 7 · Reserve (%): 30 · Other PoE devices (pcs): 4 · Power per device (W): 5 → Total PoE draw: 89 W

What is a PoE budget?

The PoE budget is the total power a switch can deliver to all its PoE ports at once, for example 120 W. Each port also has its own limit by standard: 15,4 W for PoE (802.3af), 30 W for PoE+ (802.3at) and 60–90 W for PoE++ (802.3bt).

Why add a reserve?

Devices draw more when they start up, heat up or use features such as infrared lights on cameras. A reserve of 20–30 % keeps the switch from turning off ports when the budget runs out and leaves room for another device later.