CCTV Storage & Bandwidth Calculator
Estimate how much storage your surveillance system needs based on camera quality, recording behavior, and retention period.
Why use a CCTV calculator?
A CCTV calculator helps you avoid two expensive mistakes: buying too little storage and losing footage too early, or overbuying hardware you do not actually need. With modern IP cameras, the storage impact of small choices (codec, FPS, resolution, and recording strategy) can be significant. A simple estimate before installation can save budget and reduce redesigns later.
What this calculator estimates
- Bitrate per camera based on resolution, codec, frame rate, and scene complexity.
- Total live bitrate for NVR throughput and network planning.
- Average recorded bitrate adjusted by schedule and motion activity.
- Total storage required over your selected retention period, including overhead.
Key inputs explained
1) Resolution, codec, and frame rate
Higher resolution means better detail, but also higher bitrate. Codec choice matters too: H.265 usually reduces storage compared to H.264 at similar visual quality. FPS controls smoothness; for many security scenarios, 12–15 FPS is enough, while entrances, cash points, or traffic may need more.
2) Continuous vs motion recording
Continuous recording is simple and predictable, but consumes more storage. Motion-based recording can dramatically reduce storage if the scene is quiet, though it requires good detection tuning and proper pre/post-event recording settings.
3) Retention target
Retention depends on policy, compliance, and risk profile. Retail might keep 30–90 days, while some industrial or regulated environments require longer archives. Always confirm legal and insurance requirements before final sizing.
Storage sizing formula (simplified)
The core estimate is:
Total Storage = Average Recorded Bitrate × 10.5469 × Retention Days × (1 + Overhead) / 1024
Where 10.5469 converts Mbps to GB/day. This is an engineering estimate, not an exact disk-level forecast, because real-world bitrate is variable.
Practical deployment tips
- Use VBR (variable bitrate) with quality limits rather than fixed high CBR when possible.
- Lower FPS in low-risk zones and reserve higher FPS for critical views.
- Check night performance: infrared scenes can change compression behavior.
- Keep at least 10–20% headroom in storage and NVR throughput.
- Validate with a pilot: record real footage for 48–72 hours and compare actual usage.
Example scenario
Suppose you run 16 cameras at 4MP, H.265, 15 FPS, medium scene complexity, continuous recording, and 45-day retention. If the per-camera bitrate lands around 2.7 Mbps, your storage may end up in the tens of terabytes once overhead is included. This is why many projects move from a single drive to multi-bay NVRs or dedicated storage arrays.
Final note
Use this tool as a planning baseline, then verify with live data from your exact camera models and scenes. Vendor bitrate calculators, test recordings, and retention policy reviews should all be part of your final design process.