CCTV Storage Calculator

Each camera streams video at a bitrate, in megabits per second. Storage per day is:

bitrate (Mbps) / 8 x 3,600 x hours recorded per day x activity %

Dividing by 8 turns bits into bytes. Multiply by cameras and retention days to get the total, then add overhead for the filesystem and headroom.

Activity is the share of time a camera actually records. Leave it at 100% for continuous recording. For motion-only recording, estimate how much of the day has motion: a busy entrance might be 50%, a back hallway 10%.

The default is 8 cameras at 4 Mbps, recording 24 hours a day for 30 days with 10% overhead:

• Per camera per day: 4 / 8 x 3,600 x 24 = 43,200 MB = 43.2 GB
• Video data: 43.2 x 8 x 30 = 10,368 GB = 10.37 TB
• With 10% overhead: 11.40 TB (10.37 TiB)

Switch the same cameras to motion recording at 30% activity and the provisioned storage drops to about 3.42 TB.

Check the stream settings in the camera or NVR. As a rough guide, 1080p H.264 at 15 to 30 fps is often 2 to 6 Mbps and 4K is often 8 to 16 Mbps. H.265 usually needs about half the bitrate of H.264 for similar quality.

No. The result is the usable space you need. If the NVR uses RAID 5 or RAID 6, add the parity disks on top, for example with the RAID calculator.

Variable bitrate streams can spike well above their average at night (image noise) or in busy scenes. Measure the real average bitrate over a day and enter that.