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CCTV Storage Calculator

Works for both old-style analog HD-CCTV (DVR, coax cable — D1, 960H, AHD/TVI/CVI) and modern IP camera (NVR, network) systems. Pick your system type below and get the exact hard drive size for your retention period.

Your setup

Storage needed

Full retention period, incl. 10% buffer —TB
Per-camera bitrate—
Total network bandwidth—
Storage per day (all cameras)—
Recommended drive size: —

Analog vs. IP — why storage math differs

Older analog HD-CCTV systems (recorded through a DVR over coax cable, using AHD, TVI, or CVI signaling) top out at lower resolutions and typically only support H.264 compression — no H.265 or smart-codec options. IP camera systems (recorded through an NVR over network cable) support far higher resolutions and modern codecs. This calculator switches its resolution list and codec options based on which type you pick, so the bitrate estimate matches your actual hardware.

Formula: Storage (GB) = bitrate (Mbps) ÷ 8 × 3600 × recording hours/day × retention days, summed across all cameras — same underlying math as our NVR Storage Calculator, just with a resolution/codec table that covers analog HD-CCTV hardware too.

Analog HD-CCTV resolution reference

FormatApprox. bitrate (H.264)Typical use
D1 (704×480)~2 MbpsLegacy analog, low detail
960H~2.5 MbpsSlightly wider legacy analog
720p (AHD/TVI/CVI)~3 MbpsEntry-level HD-CCTV upgrade
1080p (AHD/TVI/CVI)~4 MbpsMost common HD-CCTV install
4MP (TVI/CVI)~6 MbpsHigher-end coax-based systems

IP camera resolution reference

ResolutionApprox. bitrate (H.264, 30fps)
2MP (1080p)~4 Mbps
4MP~6 Mbps
5MP~7 Mbps
8MP (4K)~12 Mbps

Upgrading from analog to IP?

If you're quoting a system replacement (swapping an old analog DVR setup for IP/NVR), run the numbers for both system types with the same camera count and retention period — it makes the storage-capacity jump concrete for the customer, not just a "better picture quality" pitch. For network sizing on the IP side, follow up with the IP Camera Bandwidth Calculator to size the switch and NVR ports.

Note: analog HD-CCTV bitrates vary more between manufacturers than IP camera bitrates do — always sanity-check against your specific DVR/camera datasheet before ordering a drive on a large or long-retention job.

Related guide

Not sure whether analog or IP is the right call for this job in the first place? See Analog vs. IP CCTV in 2026: Which Should You Actually Install for an honest, experience-based breakdown of when each one genuinely makes sense.

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