taap.digitalnetwork engineering toolkit

How many PoE watts do I need for 8 IP cameras?

Answer
123 W at the switch (class 3 (802.3af))

8 IP cameras on class 3 (802.3af) (15.4 W per port at the switch) add up to 123 W. Using the 80% rule, pick a switch with a PoE budget of at least 154 W.

poe-budget · adjust the values
W
W

Budget by quantity

QuantityDrawRecommended budget
461.6 W77.0 W
8123 W154 W
16246 W308 W

Values are the class maximum on the switch side (PSE). Real draw is usually lower, but the switch reserves the class power.

More questions like this

Frequently asked questions

Do cameras really draw that much?

Not always: a typical dome camera draws 4–8 W, but IR and heaters push it up. Size by class so you don't fall short.

How far does PoE reach?

Up to 100 m of twisted pair (Cat5e or better). Beyond that, use a PoE extender or fiber.