Work out the recorder hard drive size and network bandwidth your system needs — by camera count, resolution, codec, frame rate and retention.
Storage needed
2.4 TB
Suggested: 1 × 3 TB
Recording bandwidth
14.7 Mbps
All cameras, main stream
Per camera / day
10 GB
At your recording mode
The calculator multiplies a typical encoder bitrate for your resolution and codec by frame rate, camera count, recording mode and retention period. H.265 roughly halves H.264 storage at the same quality; motion-triggered recording typically stores 30–50% of continuous footage depending on how busy the scene is.
Treat the result as a planning figure: real bitrates vary with scene complexity, night mode and encoder settings. Round up to the next drive size, and remember surveillance recorders should use surveillance-rated drives (WD Purple, Seagate SkyHawk) rather than desktop disks.