Useful Installer Tools · CCTV

CCTV PoE Power Budget Calculator

Add cameras and other PoE devices, their quantity and expected power draw, then compare the total demand with the PoE switch budget. The calculator shows total device load, reserve-adjusted requirement, remaining headroom, port usage and a practical minimum PoE budget recommendation.

PoE switch and connected devices

Enter the switch power budget, reserve you want to keep, then add each camera or PoE device. Use the device's actual maximum power specification whenever available.

Switch PoE budget (W)

PoE ports available

Safety reserve (%)

Use the equipment datasheet: Camera IR LEDs, heaters, illuminators, PTZ motors, Wi-Fi radios and accessories can raise power draw above the normal daytime value. Enter the device's maximum expected watts rather than an idle measurement.

Installer guide

How to size a PoE switch correctly.

A switch can have enough ports but still have too little total PoE power. Check both.

01Use maximum device wattsCheck each camera or device datasheet. Night IR, PTZ movement and heaters can increase consumption.

02Count every powered portCameras, access points, intercoms, PoE extenders and other powered devices all consume from the same switch budget.

03Keep reserveRunning a switch permanently at its exact maximum leaves little room for startup peaks, temperature, ageing or future expansion.

04Check per-port capabilityA high-power PTZ may need a stronger PoE port even when the switch has plenty of total wattage remaining.

05Check port countTotal watts can be fine while the switch still has too few physical PoE ports for the project.

06Cable mattersLong or poor-quality copper runs increase voltage drop and can make marginal devices unstable. Use proper structured cabling.

07Plan future camerasWhen practical, leave spare power and ports for expansion instead of replacing the switch later.

08Verify switch documentationSome switches have different power limits on different ports or operating modes. Confirm the actual model specification.

09Test after installationCheck cameras at night with IR active and exercise PTZ devices so the system is tested near real maximum demand.