CCTV Retention Days from Disk Capacity
How many days of footage a given NVR disk holds, from camera count, bitrate, and recording schedule (the inverse of the storage calculator).
Formula and source
Retention days = disk_capacity_GB / (cameras * bitrate_Mbps * 0.45 * recording_hours); the algebraic inverse of the NVR storage relation (1 Mbps for 24 h = 10.8 GB/day). Recording hours = 24 continuous, or 24 * duty% for motion.
IP-video retention from available disk, camera count, bitrate, and recording hours (days = disk_GB / (cameras x bitrate x 0.45 x hours); 1 Mbps for 24 h is about 10.8 GB/day), per the standard NVR/VMS sizing practice; first-principles bitrate accounting.
Audience
This tile is built for electricians and the adjacent professions in the Electrical group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
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Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.