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).

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.

First-principles bitrate accounting. The H.264/H.265 bitrate estimates are scene- and vendor-specific and user-supplied; the VMS calculator and the installed cameras govern.

Estimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.

Field names used by the API: disk_capacity_gb, camera_count, bitrate_mbps, recording_mode, retention_days, daily_total_gb

• Bitrate per-camera bitrate is user-supplied or estimated from resolution/fps/codecVMS sizing practice