CCTV Storage Calculator for 30-Day NVR Retention
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Calculate CCTV storage for 30-day retention, NVR sizing, H.264/H.265/MJPEG bitrate, RAID headroom, and commercial camera design review.
Use this CCTV storage calculator to estimate recorder capacity before buying an NVR, VMS server, or storage array. For commercial perimeter projects, use the result as a design-review input, not as a final quote.
The core formula is Storage (TB) = cameras x bitrate (Mbps) x recording seconds x retention days / 8 / 1,000,000. After calculating the base number, add headroom for RAID, formatting, metadata, night noise, weather, and future cameras. For perimeter systems, connect the retention plan to FortSense 4, camera verification, and a scoped design review.
Enter the camera count and the average recorded bitrate in Mbps for each stream.
Set recording hours per day and retention days, especially for 30-day or 90-day policies.
Compare codec assumptions such as H.264, H.265, and MJPEG against real camera output.
Add headroom for RAID, night noise, weather, busy gates, and future camera expansion.
Use the calculated TB figure as the starting point for a design review when the project includes perimeter alarms or many cameras.
Engineering Estimate Only. Bitrate varies by scene complexity.
Validate final specs with manufacturer ferramentas.
Multiply camera count by average bitrate, recording seconds per day, and 30 days, then divide by 8 to convert bits to bytes and by 1,000,000 to estimate terabytes. Add headroom for RAID, formatting, metadata, night noise, and camera expansion.
It depends on the encoded bitrate, not resolution alone. A 4K H.265 camera recording continuously at 8 Mbps for 30 days uses about 2.6 TB before RAID and overhead; at 4 Mbps it uses about 1.3 TB.
Vendors often advertise disk capacity in TB, while operating systems may show TiB. For procurement, calculate in TB and keep extra headroom so the TB/TiB difference does not break the retention target.
Average bitrate, recording mode, retention days, scene motion, night noise, frame rate, codec, and camera count usually change storage more than the camera resolution label by itself.
H.265 usually reduces storage at similar quality, but actual savings depend on the camera encoder, scene complexity, VMS compatibility, GOP settings, and whether the client systems can decode it reliably.
Request a design review when the system protects a commercial perimeter, needs 30-90 day retention, includes many cameras, or must tie video retention to alarm verification and operator response.
Yes. Use it to estimate storage for cameras that verify fence-line alarms, gates, yards, substations, or other perimeter zones, then validate the design against actual bitrate samples and response workflows.