Camera storage and recording time calculation
Storage cannot be selected from megapixels alone. Use the actual bitrate, number of cameras, recording mode, required retention and a realistic safety margin.
Core formula
Daily GB per camera is approximately bitrate in Mbit/s × 86,400 ÷ 8,000. Multiply by camera count and days. Motion recording also needs an estimated activity share. Add 10–20 percent for night noise, busy scenes and profile variation.
Four-camera 4K example
Four 8 MP cameras at 6 Mbit/s each create about 259 GB per day continuously. Thirty days is about 7.8 TB, or roughly 9 TB with 15 percent reserve. A 10 TB surveillance drive or multiple NVR bays would be sensible.
Why real use varies
Variable bitrate responds to the scene. Night noise, FPS, WDR, audio and quality settings may increase storage. Check the NVR's measured daily volume after commissioning and update the plan if needed.
Choose the storage medium
Surveillance HDDs are designed for continuous writes. Confirm maximum capacity per NVR bay. SSDs are quiet but cost more per terabyte, while memory cards are better suited to local backup or single-camera recording.
Frequently asked questions
How much does one 4K camera use per day?
At 6 Mbit/s, about 65 GB continuously; scene and codec change the result.
Is motion retention exact?
No. It depends on how often the scene triggers recording.