Free Tool · Updated 2026
CCTV Storage Calculator
Work out exactly how much NVR hard drive storage your camera system needs, based on camera count, resolution, frame rate, compression and how many days of footage you want to keep.
Want an exact number, not an estimate?
This calculator gives a strong planning estimate. For an exact, guaranteed figure, our engineers confirm everything during a free site survey.
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النسخة العربيةHow this calculator works
CCTV storage capacity depends on five variables: camera count, resolution, frame rate, compression format, and whether the system records continuously or only on motion detection. This calculator combines all five into a single estimate using typical H.265 compression rates, the standard used by virtually all modern CCTV systems sold in the UAE today.
Why getting storage right actually matters
An undersized hard drive is one of the most common and expensive CCTV mistakes. The system records perfectly, the cameras work fine, but the NVR silently overwrites old footage long before you expect it to, because the hard drive was never sized for your actual camera count and resolution. The first time you need footage from three weeks ago and discover it's gone is the worst possible moment to learn this.
Continuous vs motion-triggered recording: which should you choose?
Continuous (24/7) recording captures everything, with no risk of missing an event due to a motion sensor not triggering in time, but requires roughly 2.5x more storage than motion-triggered recording. Motion-triggered recording only records when the camera detects movement, dramatically reducing storage needs, but depends on motion sensitivity being correctly tuned; too sensitive and it records constantly anyway, too insensitive and it can miss the start of an event. Most villa and small office installations use motion-triggered recording on secondary cameras and continuous recording only on the highest-priority points like the main gate.
Resolution vs retention period: the trade-off
Higher resolution cameras produce dramatically more data. Going from 2MP to 8MP roughly quadruples file size per camera. If your budget or hard drive capacity is fixed, you generally get better results from fewer high-resolution cameras at your most important points (main gate, entrance) combined with standard resolution elsewhere, rather than uniform high resolution across every camera, which can force you to shorten your retention period to fit the same hard drive. For a full breakdown of how many cameras you actually need before sizing storage, see our guide on how many CCTV cameras you need.
Use this number as a starting point, not a final quote
This calculator gives a solid planning estimate based on typical compression rates, but actual storage needs vary with scene complexity (a busy street view records more data than a quiet garden corner) and your NVR's specific encoding efficiency. The only way to get a guaranteed, exact recommendation is during a site survey, where we also confirm camera placement and count for your specific property.
Frequently asked questions
For 8 cameras at 4MP, motion-triggered recording, and 30 days retention, expect roughly 1-2 TB of storage, though continuous recording or higher resolution will increase this significantly. Use the calculator above for a number matched to your exact setup.
1TB is generally enough for a small system (2-4 cameras) with motion-triggered recording and standard retention, but is often insufficient for 8+ cameras or continuous recording setups.
30 days is a common standard for villas and small businesses, balancing storage cost against having enough history to investigate an incident. Higher-security commercial sites sometimes retain 60-90 days.
Yes, H.265 typically reduces file size by 40-50% compared to H.264 at the same resolution and quality, which is why nearly all modern NVRs default to H.265 or H.265+ compression.