Free tool · UK
CCTV storage calculator
Output: required recorder drive capacity (TB) and network bandwidth (Mbps). Inputs: number of cameras, resolution, codec, frame rate, recording mode, retention period.
Storage needed
2.4 TB
Suggested: 1 × 3 TB
Recording bandwidth
14.7 Mbps
All cameras, main stream
Per camera / day
10 GB
At your recording mode
Stocked drives that meet this figure
All storage- 3 TB3TB - HDD 3.5" SATA Hard Drives - Ideal for 24/7 continuous recording£93.67
- 4 TB4TB - HDD 3.5" SATA Hard Drives£105.67
Surveillance-rated drives are designed for continuous writing. A desktop disk used in a recorder is the most frequent cause of drive failure in the second year.
Calculation method
Storage = typical encoder bitrate for the selected resolution and codec × frame rate × camera count × recording mode × retention period. Codec: H.265 requires about half the storage of H.264 at equal quality. Recording mode: with motion triggering, stored footage is typically 30–50% of the continuous total; a busier scene gives a higher share.
The result is a planning estimate. Variables that change the actual bitrate: encoder settings, night mode, scene complexity. Round up to the next standard drive size. Drive type: surveillance-rated (Seagate SkyHawk, WD Purple); desktop disks are not suitable.