Useful numbers. Clear assumptions.

Estimate first. Verify device specifications before buying or installing.

Recording storage

CamerasMbps per cameraHours/dayRetention days

Average bitrate × recording time, plus 10% overhead. Decimal TB; no RAID allowance.

PoE devicesWatts/deviceSwitch budget (W)

Includes 20% reserve. Check per-port standards, port count, IR/heater peaks and cable limits separately.

Distance (m)Horizontal FOV (°)

Width = 2 × distance × tan(FOV/2). Flat-plane geometry; no walls, height or distortion. Not an image-detail guarantee.