How to calculate monitoring storage capacity: comparison of resolution, bit rate and storage days

Calculation formula

Single channel daily capacity (GB) ≈ bit rate (Mbps) ÷ 8 × 86400 seconds ÷ 1024 × 1.1

Dividing by 8 is to convert bit to Byte, and 1.1 is the additional overhead of the file system and index.

Simplified to facilitate mental arithmetic: Single channel per day (GB) ≈ bit rate (Mbps) × 11.6

Cheat sheet (single channel · saved for 30 days)

Estimation example

A certain project has 32 channels of 4 million cameras, a bit rate of 4Mbps, and is required to be saved for 30 days:

32 × 46 GB × 30 ≈ 44,160 GB ≈ 43 TB. Considering formatting loss and redundancy, it is recommended to configure 48 to 52 TB. For example, eight 8TB surveillance hard drives (approximately 64TB raw capacity).

Precautions for selection

• Use a dedicated hard disk for monitoring: Supports 7×24 continuous writing. Ordinary desktop disks are prone to disk failure under multi-channel concurrent writing.
• Leave redundancy: The actual capacity used is not recommended to exceed 85% of the total capacity to avoid fragmentation and write failures.
• Formatting loss:There is a difference of about 7% to 10% between the nominal capacity of the hard drive and the actual available capacity.
• Double backup of important channels: NVR dual-disk hot backup or separate storage of key channels can be used.
• Tiering on demand: 90 days for key areas and 30 days for ordinary areas, which can significantly reduce the overall cost.