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Security & Surveillance Tool

NVR Storage Calculator

Work out how much drive capacity an NVR needs for your cameras — daily footage, retention period, and RAID overhead, down to a recommended drive size.

Updated: July 7, 2026Planning reference

Quick Answer

Storage is bitrate × time — the same per-camera bitrate as the Bandwidth Calculator, over your retention period.

Add camera rows exactly like the Bandwidth Calculator, set recording hours and mode, pick a retention target and optional RAID level, and get the raw and recommended drive capacity to buy.

Recording Settings

Recording, retention & RAID

These apply to every camera row below.

Motion-only recording is a space-saving buffer, not a sizing strategy — design continuous recording for critical areas, since motion detection can miss the seconds right before an event triggers.

Cameras

Camera list

Same per-camera model as the Bandwidth Calculator — resolution, codec, fps and quantity.

LabelResolutionCustom MPFPSCodecQtyGB/day

Planning estimate

Real bitrate depends on scene content, camera firmware and codec tuning — datasheet figures are lab maximums. This calculator assumes medium scene complexity per camera; verify against your actual cameras before purchasing drives.

Formula / Method

How the calculator works

Each camera's Mbps is computed exactly as in the Bandwidth Calculator (resolution × fps × codec × scene), then converted to daily storage using the field-standard constant of 10.8 GB/day per Mbps, scaled by recording hours/day and the recording-mode factor. Daily totals across all cameras are multiplied by your retention period for raw footage, divided by the RAID array's usable fraction for required raw capacity, then divided again by a usable-formatting and 90% fill-headroom factor for the recommended purchase size.

GB/day = Mbps × 10.8 × (rec.h/24) × motion factor · Raw TB = GB/day × retention ÷ 1000

Inputs

Required inputs

Per camera row: resolution, custom MP if needed, frame rate, codec and quantity. System-wide: recording hours/day, recording mode (continuous or motion-only), retention days, optional RAID level with drive count, and optional drive size to get a drive count.

Uses

Where this helps

Sizing NVR drive bays before purchase, comparing retention targets against available budget, checking whether an existing array covers a compliance-driven retention period, and planning RAID rebuild capacity ahead of time.

FAQ

Storage notes

How is storage linked to bandwidth?

Storage is bitrate × time. This calculator uses the exact same per-camera Mbps model as the IP Camera Bandwidth Calculator, then multiplies by 10.8 GB per Mbps per day of recording, over your retention period. If you already ran the Bandwidth Calculator, the two stay consistent by design.

Does RAID reduce my usable space?

Yes. RAID 1 (mirroring) gives you 50% of raw capacity, RAID 5 gives (N−1)/N (losing one drive's worth across the array), and RAID 6 gives (N−2)/N (losing two drives' worth, for extra rebuild safety). Buy raw capacity accordingly — the "required raw" figure already accounts for this.

Should I size for motion-only recording?

Design to continuous for critical areas. Motion-only recording saves real space, but it's a buffer against running out of storage, not a guaranteed capture strategy — pre-event seconds and low-contrast motion can be missed depending on detection sensitivity and camera firmware.

Learn More

Reference links

Project

Need help sizing an NVR or storage array?

ITCOREOPS can support camera network design, NVR/storage sizing, RAID planning and infrastructure documentation.

Open project formVisit ITCOREOPS →

Disclaimer

Planning reference only

Planning-level estimate using the field-standard 10.8 GB/day-per-Mbps constant and RAID usable-capacity math. Real bitrate depends on scene, firmware and codec tuning — not a datasheet or guaranteed figure. Verify against your actual cameras and NVR/storage system.

Workflow

Check storage before specifying drives or committing to a retention policy.

Use this calculator before purchasing NVR drives or signing off on a retention period, so shortfalls surface on paper, not when the array fills up.

Use exact inputs ↑

Support

Need help with NVR or storage planning?

For camera network design, NVR sizing, RAID planning and operational infrastructure support, visit ITCOREOPS.

Visit ITCOREOPS →Email ITCOREOPS ✉

Feedback

Found a bug or calculation issue?

Report display problems, calculation issues or suggestions for improving this calculator.

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Worked example

Inputs: 8× 4MP cameras @ 15 fps, H.265, continuous 24 h/day, 30-day retention, RAID 5 on 4 drives.

Result: per camera ≈2 Mbps → 2 × 10.8 = 21.6 GB/day; × 8 cameras =172.8 GB/day; × 30 days = ≈5.18 TB raw; ÷ RAID 5 (0.75 usable) =≈6.91 TB required raw; ÷ usable-formatting & 90% fill = ≈8.44 TB recommended. A 4-drive RAID 5 array of 6 TB drives (24 TB raw, 18 TB usable) comfortably covers this.