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BS EN 62676-4 Surveillance Storage Standard

CCTV Storage & Bandwidth Calculator

Accurately size surveillance-grade NVR hard drives (WD Purple / Seagate SkyHawk) and switch backplane throughput. Compute exact gigabytes per day and total terabytes required for continuous or AI motion recording.

4
30
30 days is the standard recommended evidential retention period for UK commercial and domestic premises.
Sizing Telemetry
Total Inbound Bitrate
9.6 Mbps
NVR switch backplane throughput requirement
Daily Storage Ingestion
31.1 GB / day
Aggregated across all active channels
Recommended HDD Capacity
1.0 TB
Fitted with 1x 1TB or 2TB WD Purple / SkyHawk drive (85% safe margin).
Engineer Tip: Desktop PC drives (Seagate BarraCuda / WD Blue) fail within 12–18 months in NVRs due to 24/7 continuous rotational vibration. Always fit 24/7 surveillance drives.

Understanding CCTV Storage & Compression Math

Surveillance storage calculations are governed by the relationship between raw sensor pixel resolution, compression efficiency, and dynamic motion duty cycles:

Daily Storage (GB) = [ (Camera Bitrate kbps × Compression Factor × Channels) / 8 ] × 86,400s × Duty Cycle / 1,000,000

Why H.265+ Outperforms Standard H.264: Traditional H.264 streams encode repetitive background data (such as stationary brick walls or empty driveways) in full I-frames at regular intervals. Hikvision and Dahua Smart H.265+ algorithms analyze surveillance scenes, generating long Group of Pictures (GOP) intervals and referencing static backgrounds. This reduces storage consumption by up to 70% without sacrificing 4K evidential facial clarity.

Need Bespoke Commercial or Residential CCTV Sizing in Yorkshire?

We supply and commission 4K ColorVu IP systems, NVRs with surveillance-grade storage, and Cat6 cabling across Leeds, Bradford, Wakefield, Huddersfield, and surrounding towns.

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Need On-Site Engineering in Yorkshire?

Gary Pearce • 25+ Years Experience • £10M Public Liability • CAI-Benchmarked Materials