Dahua DH-IPC-EBW81242N (12MP Fisheye) storage & retention

The 12MP sensor is the storage driver here: at 16 Mbps typical bitrate on H.265, a single DH-IPC-EBW81242N writes about 173 GB per camera per day when recording continuously. H.265's smart-codec efficiency is what keeps that figure workable at all — the same 12MP fisheye stream on plain H.264 would typically need roughly 1.5-2x the bitrate for comparable image quality, pushing daily storage well past 250-300 GB per camera and forcing a larger NVR class far sooner.

Scaling from there is linear and easy to reason about: 16 cameras x 173 GB/day x 30 days works out to approximately 83 TB. Add more cameras or extend retention beyond 30 days and the total grows in direct proportion — double the retention to 60 days and the figure roughly doubles too. At 16 cameras of this class, the resulting capacity and channel count sit within an Entry NVR bracket rather than a mid-tier or enterprise head-end.

Use the calculator by adjusting camera count, retention days, and recording schedule to see the storage total recompute live. Switching from an always-on schedule to a motion-only or scheduled-hours profile applies a duty-cycle factor that can meaningfully cut the daily figure, since the camera is not writing continuously through empty periods.

What the calculator does not decide: real scene activity (foliage, traffic, crowding) pushes actual bitrate above or below the 16 Mbps typical figure the manufacturer quotes; it does not add RAID or redundancy overhead, which increases usable-to-raw capacity needs; it does not size a failover or off-site archive tier; and it does not check whether the head-end's network write throughput or drive bays can sustain the ingest — those remain a design-stage decision alongside the raw capacity number.