Security Camera Storage Calculator
Estimate how many gigabytes or terabytes of storage your cameras need from bitrate, camera count and retention period.
Storage requirements are driven primarily by bitrate, camera count, hours recorded per day and retention period. Resolution matters indirectly because higher resolution often means a higher bitrate.
Formula
Approximate GB = cameras × bitrate in Mbps × 3,600 seconds × recording hours × days ÷ 8 ÷ 1,000. Real systems differ because compression efficiency, variable bitrate, motion-only recording and audio change actual use.
Continuous vs motion recording
Continuous recording is predictable and storage-heavy. Motion recording can cut storage dramatically, but the result depends on scene activity. A busy sidewalk and an empty backyard will not produce the same retention from the same drive.
Headroom
Do not size a recorder to the exact theoretical number. Leave margin for bitrate spikes, added cameras and longer-than-planned retention.