CCTV Storage Calculator

Storage for camera systems is arithmetic, not guesswork: cameras × bitrate × hours × days. Enter a home setup or a forty-camera site and get the terabytes, a drive layout, and the assumptions written out — because a retention target you cannot defend is not a plan.

Cameras

Average bitrate per camera (Mbps) 1080p ≈ 2–4, 4K H.265 ≈ 6–10

Recording hours per day per camera

Retention (days)

Recording mode

Capacity reserve (%)

RAID layout (optional)

Record audio (adds 64 kbps per camera)

Per camera per day

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Total footage (retention target)

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Recommended capacity

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Retention trade-off (same cameras and bitrate):

Retention	Footage	With reserve

Assumptions this result depends on — change the inputs if any is untrue:

Planning a surveillance project for a business or client? The calculation above is free and always will be. If you want a scoped storage design — camera counts, retention policy, drive classes and a bill of materials — send the details below and our team follows up. We also cover this engineering side at woCyber.

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How the calculation works

Continuous recording per camera: GB/day = Mbps × hours × 3600 ÷ 8 ÷ 1000 (decimal GB). Multiply by cameras and retention days for the footage total; add your reserve for file system overhead, snapshot space and bitrate spikes. Audio adds a constant 64 kbps per camera when enabled. Event mode multiplies the hours by your recording ratio — the tool asks for the ratio instead of pretending every triggered camera records ten percent of the day.

The retention table shows the same system at 7, 14, 30, 60 and 90 days so the cost of each extra week is visible. When a RAID layout is selected, the tool sizes the smallest standard drive set that reaches the target and reports raw versus usable honestly.

What bitrate should I enter for my cameras?

Use the camera's main-stream setting, not the marketing number. Common averages: 1080p H.264 around 2–4 Mbps, 2K around 4–6 Mbps, 4K H.265 around 6–10 Mbps. Busy scenes exceed the average — that is what the reserve percentage is for.

Continuous or event recording — which should I model?

Model what your recorder actually does. Continuous is simpler and conservative. Event mode saves a lot of space, but only if your recording ratio is honest: a driveway camera that triggers fifty times a day may record twenty percent of the time, not five.

Does RAID change how much footage I can store?

Yes — the same way as any NAS: usable capacity is what survives the layout. The tool sizes a drive set for the retention target you entered and shows raw versus usable for that array.

Do you build surveillance storage for companies?

This site is an independent publication; the inquiry form below routes project questions to our team, who also cover surveillance storage engineering at woCyber. The calculator and every result on this page work without submitting anything.

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