How Much CCTV Storage Do You Actually Need for 4, 8, or 16 Cameras?
H.265 compression, frame rate, resolution and continuous vs motion recording. Calculate exact HDD storage for your security setup.
One of the most common mistakes when buying a CCTV package is underestimating hard drive capacity. Nobody wants to discover that their recorder only kept 3 days of footage when an incident occurred last week.
The role of H.265 and H.265+ compression
Older systems used H.264 compression, which required 40–50 GB per day for a single 1080p camera. Modern H.265+ encoding cuts that bandwidth and storage by up to 70%, allowing you to store weeks of video on a single 1TB or 2TB drive.
Storage rule of thumb by channel count (at 1080p H.265)
- 4-Camera setup: 1TB gives roughly 12–15 days continuous; 2TB gives 25–30 days.
- 8-Camera setup: 2TB gives roughly 12–14 days; 4TB gives 25–30 days.
- 16-Camera setup: 4TB gives 12–15 days; 6TB–8TB gives 25–35 days.
Continuous vs Motion-Activated recording
Enabling smart motion detection or scheduled recording can double or triple your retention time, because quiet hours with zero activity use virtually no disk space.
Always choose surveillance-grade drives (WD Purple / Seagate SkyHawk)
Never install a desktop PC hard drive in a DVR. Surveillance drives like Western Digital Purple and Seagate SkyHawk are engineered for 24/7 continuous write cycles and withstand the heat of sealed NVR enclosures.