Quick answer
Storage is driven mostly by bitrate and retention. Eight cameras at 4 Mbps recording all day for 30 days need about 10.4 TB before extra headroom or RAID overhead.
Best for: comparing realistic scenarios before acting. Not for: final professional guidance, emergency decisions, or replacing product labels and local requirements.
How to use the calculator
- Enter the labeled inputs for this surveillance storage scenario.
- Adjust the optional assumptions shown in the form instead of relying on defaults blindly.
- Read the primary result, supporting result cards, and any warning notes together.
- Use share, copy, or print/PDF to save the exact scenario for later comparison.
What the results mean
Start with the displayed CCTV / Surveillance Storage Calculator values, then read its assumptions and limits before acting. Supporting cards show the inputs, ranges, assumptions, or follow-up checks that explain how to interpret it.
Decision notes for this calculator
How to interpret this calculator
The labeled inputs and visible assumptions drive the result.
Sources and assumptions
Use the inputs, units, and assumptions shown on the page, then compare important results with product documentation, vendor guidance, local code, or a qualified professional when the decision has safety or cost consequences.
- NIST binary prefixes and SI units
- SNIA Dictionary for storage terminology
- CalculatorShelf source guide: storage formulas
Method version: SURVEILLANCE_STORAGE-1.0. Send corrections through the contact page.
What to do next
Compare the estimate with camera bitrate settings, NVR retention rules, motion recording, redundancy, and spare drive capacity.
Save this scenario
Use Share, Copy result, or Print / PDF to keep the exact inputs with the result. If something looks wrong, report an issue with the Surveillance Storage Calculator.
Calculate CCTV storage for retention days
This CCTV storage calculator estimates how much recording space a security camera system needs before footage starts rolling off. It is useful when cameras, NVR settings, and retention requirements are known but drive size is still undecided.
- Inputs: camera count, bitrate, recording hours per day, retention days, motion-recording percentage, and FPS note.
- Outputs: total storage, storage per day, storage per camera, recommended raw drive size, and average throughput.
- Best use: compare 24/7 recording, motion-based recording, different bitrates, and different retention periods.
- Limitations: codec, scene complexity, variable bitrate, audio, RAID overhead, NVR reserves, event clips, and legal retention rules can change the final drive plan.
For related planning, compare the memory card calculator, download time calculator, and NAS capacity calculator.
Plan security camera retention from bitrate
This surveillance storage calculator is for questions like “how much storage do eight 4 Mbps cameras need for 30 days?” It uses entered bitrate directly, so it works for H.264, H.265, 4K, 1080p, or mixed camera systems when you know the sustained Mbps per camera.
- Inputs: camera count, bitrate, recording hours per day, motion-recording percentage, retention days, and optional storage overhead.
- Outputs: total storage, storage per day, storage per camera, and practical headroom notes.
- Related: compare single-card camera planning with the memory card calculator and file-transfer planning with the download time calculator.
Formula / methodology
Storage uses the bitrate field directly: GB = bitrate Mbps × 1,000,000 ÷ 8 × seconds recorded × cameras × motion-recording percentage ÷ 1,000,000,000. FPS and compression are displayed as planning notes only unless a additional bitrate-estimation model is added.
Assumptions and limitations
- Inputs are assumed to be measured accurately and entered in the units shown.
- Rounding is intentional so the result is easier to use in real decisions.
- Vendor-specific behavior, local code, product labels, and regional pricing can override a generic calculator.
- Health, legal, tax, emergency, structural, chemical, and other high-risk decisions need qualified guidance beyond a web calculator.
Example calculation
Input: 8 cameras, 4 Mbps each, 24 hours/day, 30 days, 100% recording. Output is about 10.4 TB total storage, about 346 GB/day, before RAID or filesystem overhead.
Common mistakes
- Changing FPS or compression and expecting storage to change when bitrate is entered directly.
- Using resolution instead of measured camera bitrate.
- Forgetting retention days or motion-recording percentage.
- Buying exactly the calculated capacity with no filesystem/RAID headroom.
FAQ
What formula does this page use?
Storage = bitrate × seconds recorded × cameras × retention days. Convert bits to bytes, then to GB/TB. Motion recording reduces the recorded-time percentage.
What changes the result the most?
Camera count, bitrate, recording hours, retention days, and motion-recording percentage drive storage more than frame-rate labels alone.
How should I use this result?
Use it as a planning estimate and compare important decisions with product documentation, labels, quotes, local code, or qualified guidance.
Why does this page show warnings?
Warnings call out assumptions that can materially change the result or create safety, cost, or reliability problems.
Can I share this scenario?
Yes. The share button copies a URL with the current inputs, while the main page remains the base calculator URL.
Method details
Updated: June 24, 2026. Calculation method: SURVEILLANCE_STORAGE-1.0. Availability: interactive calculator.