CCTV Storage Calculator
Size recording storage from bitrate, cameras and retention days.
Free to use · Live results · Transparent formulasA practical answer, with clear assumptions
Estimate how much video storage your CCTV system needs. Use a measured average bitrate from the actual camera stream whenever possible; resolution and codec alone do not determine the recording size.
How to use this calculator
- Enter the number of cameras and the average video bitrate in Mbps.
- Set retention days and scheduled recording hours per day.
- Use recording activity only if you have a measured motion-recording fraction.
- Add headroom, then check usable disk capacity after redundancy and filesystem allocation.
The calculation
Video TB = cameras × Mbps × 10⁶ ÷ 8 × hours/day × 3600 × days × activity/100 ÷ 10¹² Provisioned TB = Video TB × (1 + headroom/100)
What the result includes
- TB and GB use decimal units: 1 TB = 1,000 GB. Operating systems may display different binary units.
- Bitrate is the average recorded video rate per camera. Audio, filesystem overhead, RAID parity and redundancy are not modeled.
- Activity is the fraction of the scheduled recording time that is actually recorded. For continuous recording, use 100%.
- Variable bitrate depends on scene movement, noise and lighting. Measure over a representative period and allow extra capacity.
Common questions
Does H.265 always halve storage?
No. Savings depend on settings and scene content. This tool uses your supplied bitrate rather than assigning an assumed compression ratio.
How much storage do 8 cameras at 4 Mbps need for 30 days?
Continuous 24-hour recording produces 10.368 TB of video. With 20% additional headroom, provision at least 12.4416 TB before RAID and filesystem considerations.
Keep planning
Visualize camera coverage, compare camera specifications or check recorder requirements.
Formulas are documented on this page and implemented directly. These planning estimates should be checked against actual system measurements. Sources & methodology →