The formula
Storage needed = camera bitrate × 86,400 seconds in a day × number of cameras × number of days ÷ 8 (to convert bits to bytes).
Your camera’s bitrate is set in its configuration and depends on resolution, frame rate and compression. H.265 compression usually uses less space than H.264.
Worked examples (continuous recording)
2 Mbps per camera: about 21.6 GB per camera per day. For 4 cameras over 30 days: roughly 2.6 TB.
4 Mbps per camera: about 43.2 GB per camera per day. For 4 cameras over 30 days: roughly 5.2 TB.
2 Mbps, 8 cameras, 15 days: roughly 2.6 TB.
Real systems differ: motion-only recording needs less, higher bitrates need more.
Tips to keep storage under control
Use H.265 where supported, lower the frame rate on less important cameras, and use motion or schedule recording for low-traffic areas. Always choose surveillance-grade drives built for 24x7 recording.
Need it calculated for you?
Tell us your camera count, resolution and the retention you want, and we will size it for you. See our CCTV storage solutions.
By Good Morning Technology India Pvt. Ltd., Tilak Nagar, New Delhi. Updated 2026-11-03.