Free tool · IT & Security
CCTV storage calculator
Work out how much hard-disk space your CCTV recorder needs — and which surveillance HDD to buy — before you get a quote.
How it’s calculated
The method, in plain terms.
Each camera’s bitrate is estimated from a baseline for its resolution (H.264, medium quality, 30 fps), then adjusted for compression (H.265 ≈ 0.5×, MJPEG ≈ 6×), quality (low 0.6×, high 1.5×) and frame rate.
Storage = total bitrate × seconds recorded per day × retention days. We add 10% headroom when recommending a drive, because recorders need free space to overwrite old footage smoothly.
- Use surveillance-rated drives (for example Seagate SkyHawk or WD Purple) built for 24×7 writing.
- Lower frame rates and motion recording extend retention without changing cameras.
- Check how many drive bays your NVR/DVR has and the largest drive it supports.
How much storage does a 4-camera CCTV system need for 30 days?
With 1080p cameras on H.265 at medium quality and 15 fps, recording 24 hours a day, four cameras need roughly 1.1 TB for 30 days — a 2 TB surveillance drive gives comfortable headroom. Use the calculator for your exact settings.
Does H.265 really halve storage?
In typical scenes H.265 needs around half the bitrate of H.264 for similar image quality. Results vary with scene activity and camera settings.
What reduces CCTV storage without losing coverage?
Use H.265 or smart codecs, record at 12–15 fps, use motion or schedule recording where appropriate, and match retention to what you actually need.
Which hard disk should I use in an NVR or DVR?
Use surveillance-rated drives designed for continuous recording, sized to your retention requirement and supported by your recorder.
Get in touch
Want us to design the full system?
Send us your calculator result and site details — we’ll survey, specify the right equipment and send an itemised quote.
- Call+91 98913 73456
- Emailinfo@goldensolutions.in
- Visit5/1, New Rohtak Road, Anand Parbat Industrial Area, New Delhi 110005