CCTV and NVR storage calculator
Work out NVR hard disk capacity for your cameras, resolution and retention period.
Calculated in your browser. Nothing is sent to our servers.
Enter the number of cameras, resolution, codec, frame rate, recording hours and how many days of footage you must keep. The calculator gives the storage your NVR or video server needs, with a recommended size that includes headroom, and the total recording bandwidth.
What drives storage
Storage is bitrate × time. Higher resolution, higher frame rates and busy scenes all raise the bitrate. H.265 roughly halves the storage of H.264 for the same picture quality. Motion-only recording saves space, but plan for the busiest days, not the average.
Typical bitrates (H.264, 25 fps)
- 1080p (2 MP): 4 Mbps
- 4 MP: 6 Mbps
- 5 MP: 8 Mbps
- 4K (8 MP): 16 Mbps
Use your camera's configured bitrate if you know it.
Choosing disks
Use surveillance-rated disks built for continuous writing, and RAID 5 or 6 on larger NVRs so one failed disk does not lose footage. Remember that RAID reduces usable capacity, and many regulators and banks require 30–90 days of retention.
Common questions
How much storage do I need for 16 cameras for 30 days?
At 1080p H.264, 4 Mbps and 24-hour recording, about 21 TB. With H.265 it drops to about 10 TB.
Does motion recording really save space?
Yes, often 50–70% in quiet areas. Set the activity field to the share of time you expect motion, and leave headroom for busy periods.
What frame rate should CCTV use?
12–15 fps is enough for most areas. Use 25 fps for cash counters, entrances and anywhere you need to see fast movement.
