NVR bay and RAID planning

NVR Storage Calculator: Bays, RAID and Camera Retention

Plan an NVR at the array level instead of dividing raw capacity by camera count. This calculator accounts for codec, recording activity, drive bays, redundancy and free-space reserve.

Storage formulas reviewed August 4, 2026 Bitrate and recording activity drive capacity Exact model verification required

Quick answer

The NVR must fit the footage requirement after redundancy and reserve, not before. A four-bay unit with one parity drive has three data-bearing drive equivalents for planning purposes.

Array planningBays + paritySeparates raw and usable storage

CodecH.264 / H.265Efficiency factor included

Maximum plan32TB per driveRecorder limit must be verified

RecommendationStandard or AIBased on scale and workload

Exact model data

Current SkyHawk capacities for the calculated plan

Capacity	Model	Family	Recording	RPM	Cache	Max sustained	Workload	Warranty
4TB	`ST4000VX016`	SkyHawk +Rescue	CMR	5,400	256MB	180MB/s	180TB/year	3 years
8TB	`ST8000VX010`	SkyHawk +Rescue	CMR	5,400	256MB	180MB/s	180TB/year	3 years
8TB	`ST8000VE001`	SkyHawk AI	CMR	7,200	256MB	255MB/s	550TB/year	5 years
12TB	`ST12000VE003`	SkyHawk AI	CMR	7,200	512MB	285MB/s	550TB/year	5 years
16TB	`ST16000VE004`	SkyHawk AI	CMR	7,200	512MB	285MB/s	550TB/year	5 years
20TB	`ST20000VE003`	SkyHawk AI	CMR	7,200	512MB	285MB/s	550TB/year	5 years
24TB	`ST24000VE002`	SkyHawk AI	CMR	7,200	512MB	285MB/s	550TB/year	5 years
32TB	`ST32000VE000`	SkyHawk AI	CMR	7,200	512MB	285MB/s	550TB/year	5 years

Representative exact current models are shown. Confirm the recorder maximum drive size and exact model revision before purchase.

Live catalogue

Current exact SkyHawk and SkyHawk AI offers

Only fresh, exact-model products returned by Amazon's new-condition search are eligible. Featured prices are shown when Amazon exposes them; products with no buy box are shown as buying options. Exact family, capacity and current-model matching are enforced.

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Interactive decision tool

NVR storage and drive planner

Choose a bitrate preset or use the nearest match, then enter bay count and redundancy. The result estimates per-drive capacity and checks the current SkyHawk range.

Number of cameras Resolution and base bitrate Codec efficiency Recording hours per day Retention target (days) Recording activity Installed drive bays Drives reserved for redundancy Planning reserve (%)

What the NVR Storage Calculator calculates

The tool converts surveillance workload inputs into daily storage, target retention and a practical drive plan. It uses decimal terabytes because drive manufacturers rate capacity in base-10 units. The result includes a reserve so the recorder is not planned at 100% of nominal capacity.

Bitrate matters more than the resolution label

Two cameras with the same 4K or 1080p label can use very different amounts of storage. Scene complexity, frame rate, image quality, variable bitrate settings and night noise all affect the actual stream. Enter the recorder-reported average bitrate whenever possible instead of relying only on a resolution preset.

H.264, H.265 and H.265+ are planning assumptions

A newer codec can reduce storage, but the saving is not fixed for every scene. The calculators apply the selected efficiency factor as a planning estimate. Measure real traffic over several representative days before committing to a long retention policy.

Continuous and motion recording behave differently

Continuous recording creates a predictable 24-hour workload. Motion recording can save substantial capacity, but busy roads, trees, rain, insects and changing light can keep cameras active far longer than expected. Use a conservative activity percentage and include pre-event and post-event recording overhead.

RAID and reserve reduce usable capacity

Raw drive capacity is not the same as recording capacity. Mirroring, parity, hot spares, formatting and free-space reserve all reduce usable storage. The calculator treats redundancy drives separately and adds a planning reserve, but the recorder vendor remains the authority for the exact RAID layout.

When standard SkyHawk is enough

Standard SkyHawk is the normal direction for conventional DVR and NVR recording within the supported capacity and workload envelope. It is designed for continuous video workloads and up to 64 HD streams. Exact recorder compatibility and the published per-bay limit still need to be checked.

When SkyHawk AI becomes the better fit

SkyHawk AI is the stronger direction when the system uses AI analysis streams, needs more than 8TB per drive, has a heavier annual write workload or operates in a larger multi-bay environment. It should not be chosen merely because a camera includes motion detection.

Verify the final plan before buying

Confirm the exact recorder model, firmware, number of usable bays, maximum drive size, supported RAID mode and power supply. Then verify the exact Seagate model number in the Amazon listing and on the delivered label. Marketplace search results can substitute another family or capacity.

How Cloudzat evaluates recorder compatibility

Cloudzat separates the exact recorder model from the exact drive model. Bay count, published drive-size limits, form factor, firmware generation and storage architecture are attached to a named recorder profile. Standard SkyHawk VX and SkyHawk AI VE drives remain separate so a 5,400RPM standard model is not presented as equivalent to a 7,200RPM AI model.

Live offers are screened for new single internal 3.5-inch SATA drives. SSDs, external drives, SAS products, complete NVR or DVR systems, camera bundles, accessories, multipacks, WD Purple Pro, other Seagate families and non-new listings are rejected. A calculator result does not override the recorder manufacturer's exact compatibility list, hardware revision, firmware release notes or environmental limits.

Frequently asked questions

Surveillance storage planning questions

How accurate is a surveillance storage calculator?

It is a planning estimate. Accuracy improves when you use measured average bitrate, real motion activity and the recorder’s actual recording schedule. Variable bitrate, audio, metadata and scene complexity can change the result.

Should I enter camera resolution or bitrate?

Use measured average bitrate when available. Resolution presets are useful for an early estimate, but they cannot represent every camera, frame rate and quality setting.

How much free space should an NVR keep?

A 10% to 20% planning reserve is reasonable for early sizing. The recorder may use additional space for formatting, databases, thumbnails, analytics and file management.

Does RAID increase recording retention?

Redundancy normally reduces usable capacity because one or more drives protect the array. It can improve resilience, but it does not replace a separate backup for footage that must be preserved.

Can standard SkyHawk and SkyHawk AI be mixed?

A system may recognize both, but matching capacity, performance and workload class is generally easier to manage. Check the recorder vendor’s compatibility and RAID guidance before mixing models.

Why does the Amazon price sometimes show as unavailable?

Amazon may expose an exact product with buying options but no featured offer. Cloudzat keeps the exact listing visible without inventing a price. Open the buying-options page and verify the model, condition and seller.

Primary sources

Cloudzat may earn a commission from qualifying purchases. Product availability, pricing and specifications can change. Confirm the exact SkyHawk or SkyHawk AI model, recorder compatibility, seller, condition and regional warranty route before buying.