PoE Budget Calculator
Add up the cameras, phones and access points on a switch to see if its PoE power budget and port standard can handle them, and what size switch to look for.
Powered devices
Use the maximum power from each device's spec sheet when you have it. The figures here are typical maximums, and they run higher for cameras with infrared lights, heaters or motors.
Switch and cabling
The PoE budget is on the switch's spec sheet. It is often lower than every port running at full power, for example 370 W shared across 24 ports that can each give 30 W. Some power is lost as heat in the cable, so the switch must supply more than the devices use. PoE over twisted-pair Ethernet works up to 100 m of cable.
Estimate
| Device | Qty | Watts |
|---|
| Device | Watts each | Standard |
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The standard limits are measured at the device, after cable loss: 12.95 W for 802.3af, 25.5 W for 802.3at, 51 W for 802.3bt Type 3 and 71.3 W for 802.3bt Type 4. Some switches reserve power by device class instead of measuring real use, so they can run out of budget sooner. Check your switch's PoE settings.