Video Retention & Storage Calculator

Video Retention Storage Calculator

Video Retention & Storage Calculator

Estimate NVR storage by camera count, resolution, codec, and retention days.

Inputs

Results

Per-camera bitrate-
Combined bandwidth-
Raw storage / day-
Storage for retention-
Usable storage required-
Adjust inputs to see a configuration suggestion.

How this works

  • Each resolution maps to a typical H.264 bitrate at 30 fps. We scale linearly with framerate and apply a codec multiplier (H.265 saves ~45% over H.264 at the same quality).
  • Per-camera storage per day = bitrate × 86,400 seconds ÷ 8 (bits to bytes). Multiplied by camera count, retention days, and a motion duty factor when motion-only recording is selected.
  • RAID overhead is added at the end. RAID 5 reserves ~25% for parity; RAID 6 reserves ~50%; mirrored RAID 10 doubles raw need.
ResolutionH.264 @ 30fps (Mbps)H.265 @ 30fps (Mbps)
2MP / 1080p4.02.2
4MP6.03.3
5MP8.04.4
8MP / 4K16.08.8
12MP24.013.2
Numbers are typical for variable-bitrate (VBR) recording with a CBR cap. Scene complexity, smart codec features (Hanwha WiseStream, i-PRO Self Learning, Axis Zipstream) can cut bitrate 40-70% further on low-motion scenes.

Worked example

16 cameras at 4MP, 15 fps, H.265, 30-day retention, 24/7 recording, RAID 5:

  • Base H.265 bitrate at 4MP, 30 fps = 3.3 Mbps. Scale to 15 fps: 1.65 Mbps per camera.
  • Per-camera per day: 1.65 Mbps × 86,400s ÷ 8 = ~17.8 GB.
  • 16 cameras × 17.8 GB × 30 days = ~8.5 TB raw.
  • RAID 5 overhead: 8.5 TB × 1.25 = ~10.7 TB usable storage needed.

This fits a 16-channel NVR with 12 TB usable (4 × 4 TB surveillance drives in RAID 5) with headroom for events and growth.

Recommended IPSD products

Network Video Recorders
8 / 16 / 32 / 64-channel NVRs from Hanwha, i-PRO, Axis, Pelco, Bosch
Surveillance Hard Drives
WD Purple, Seagate SkyHawk — 4 TB to 22 TB, optimized for 24/7 recording
IP Cameras
2MP through 12MP cameras with H.265 + smart codec options
PoE Switches
Uplink capacity sized for combined camera bandwidth

FAQ

Why does the calculator default to H.265?

H.265 (HEVC) is the standard on every camera shipped in the last 5+ years and cuts bitrate roughly in half versus H.264 at the same visual quality. Stick with H.264 only when your VMS or NVR firmware does not decode H.265.

Is motion-only recording really 35% duty?

It depends on the scene. A quiet warehouse aisle may run 5-10% duty; a busy retail entrance can hit 60-80%. The 35% figure is a working average for mixed indoor commercial environments. For high-traffic outdoor scenes, treat motion-only as 24/7 for planning.

Do I need RAID for surveillance?

RAID protects against drive failure but does not replace backup. RAID 5 is the most common surveillance choice (good capacity-to-redundancy ratio). Use RAID 6 for arrays of 8+ drives because dual-disk failures during rebuild become more probable. RAID 10 is faster but halves capacity — usually overkill for surveillance.

What about audio?

Audio adds roughly 64-128 kbps per channel — less than 5% of typical video bitrate. If every camera has audio enabled and you want headroom, add 10% to the result.

How accurate is this for actual deployments?

Within ~15% for typical commercial scenes. The largest variable is scene activity. Always plan with at least 20% storage headroom for events, growth, and the inevitable retention-policy bump.

Related guides

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