CCTV hard drive storage calculator
Estimate how many terabytes you need for your recording period, or how many days an installed hard drive may retain. Enter the average bitrate per camera and daily recording hours.
Calculate CCTV storage →CCTV Storage & Security System Calculators
Plan your CCTV storage, network and camera coverage.
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From calculation to installation
Plan your CCTV storage, network and camera coverage
Use these free CCTV calculators to compare the requirements of a home, shop, office or larger security camera installation. Start with camera count and bitrate, then check the recorder, storage and network against your results.
Security camera bandwidth calculator
Estimate incoming video traffic for your NVR and upload bandwidth for remote viewing. Main streams and lower-bitrate substreams can have different requirements.
Calculate camera bandwidth →Camera lens and field of view calculator
Estimate scene width and pixel density at your chosen distance. Start with the camera’s published horizontal field of view, or enter focal length and active sensor width.
Calculate camera coverage →PoE switch power budget calculator
Check how camera count, power allocation, spare ports and uplink capacity affect the number of switches you need. Compare the estimate with the switch’s actual specifications.
Calculate PoE switch requirements →IP camera subnet calculator
Find the IPv4 network address, subnet mask, usable host range and broadcast address. Allow addresses for recorders, routers and other network devices.
Calculate an IPv4 subnet →Choose your cameras and recorder
Once you have your estimates, compare drive capacity, camera channels, incoming bandwidth and PoE support. Our team can help turn the requirements into a complete system.
Explore CCTV system builders →Worked example: 4 cameras recording for 30 days
Four cameras averaging 4 Mbps each, recording 24 hours a day for 30 days, produce approximately 5.184 TB of video. Adding a 20% storage allowance gives a target of 6.221 TB. An 8 TB total capacity is a starting point to compare, subject to the recorder’s drive support, formatting, recording overhead and any RAID configuration.
The same four cameras produce 16 Mbps of incoming video, or a 19.2 Mbps bandwidth target with a 20% allowance. These are example settings, not guaranteed bitrates for a particular resolution or codec.
Try this storage example →CCTV planning questions
Frequently asked questions
How much hard drive storage do I need for CCTV?
It depends on camera count, average bitrate, recording hours and the number of days you want to keep. The storage calculator multiplies video bitrate by recording time, then adds your selected allowance. Check the recorder’s maximum supported drive capacity and drive-bay count before choosing storage.
How many days will a 2 TB, 4 TB or 8 TB CCTV drive record?
There is no fixed recording period for a drive size. Select “Recording time” in the storage calculator and enter the installed capacity, camera count, bitrate and recording hours. More cameras or higher bitrates reduce retention; shorter recording schedules increase it.
What bitrate should I enter for a 4K or 8 MP camera?
Use the configured or measured bitrate from the camera or recorder. Resolution alone does not determine bitrate: codec, frame rate, compression settings, scene detail, movement and lighting all affect it. Include audio if it is recorded. For variable bitrate, use a representative average for storage and allow for peaks when sizing the network.
Does H.265 or motion recording reduce storage?
They can reduce recorded data, but the saving depends on the camera settings and scene. Enter the actual average bitrate rather than assuming a fixed H.265 saving. If you estimate fewer recording hours for event recording, include pre-event and post-event recording and allow for busy periods.
How much internet upload speed does remote CCTV viewing need?
Upload requirements depend on simultaneous viewers, streams per viewer and the bitrate of each viewed stream. The bandwidth calculator shows remote upload separately from camera-to-recorder traffic. A lower-bitrate substream may reduce remote viewing traffic, but other internet use and playback also need capacity.
How do I size a PoE switch for security cameras?
Check PoE port count, total power budget, per-port PoE standard and uplink bandwidth. Enter the switch-side allocation per camera, including cable loss, and allow for IR illumination, heaters or PTZ movement. The calculator checks aggregate capacity; confirm compatibility against each product’s specifications.
Can the lens calculator tell me if a camera will identify a face?
It estimates scene width and horizontal pixels per metre. Identification also depends on mounting angle, motion, shutter settings, lighting, focus and image compression. Use the camera’s published field of view and assess the actual installation; a pixel-density estimate alone is not a guarantee.
Can I use these calculators with different CCTV brands?
Yes. The calculations use the values you enter and can help plan systems using brands such as Dahua, Hikvision, HiLook, Uniview, AXIS and Ubiquiti. Always check the specific model’s recording, networking and power requirements.
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