How Long Does 1TB Last for Security Cameras?
Estimate 1TB of NVR or camera storage by camera count, bitrate, codec and recording schedule.
One terabyte can be plenty for one modest stream and very little for a multi-camera 4K system. The useful calculation is cameras × bitrate × time.
One camera, continuous recording
| Average bitrate | Approximate retention on 1TB |
|---|---|
| 2 Mbps | ~46 days |
| 4 Mbps | ~23 days |
| 6 Mbps | ~15 days |
| 8 Mbps | ~11.5 days |
Four-camera example
Four cameras at 4 Mbps each create a 16 Mbps aggregate stream. That is about 172.8 GB per day before overhead, so 1TB holds only about 5.8 days of continuous footage. The same system at 2 Mbps per camera roughly doubles that retention.
Do not size the recorder to the exact theoretical number
Reserve headroom for formatting, metadata, audio, variable bitrate and future cameras. If the goal is 14 days and the calculation says the system needs 2.4TB, a 4TB surveillance drive is usually a more sensible purchase than trying to live at the theoretical minimum.
Use the NVR Hard Drive Calculator to size a multi-camera recorder.