Inputs to confirm
- Number of cameras connected to the recorder.
- Resolution for each camera, such as 5MP or 4K.
- Continuous recording or motion-based recording.
- Target retention period, such as 7, 14, or 30 days.
Planning guide
NVR storage sizing starts with recording days.
Storage needs change with camera count, resolution, frame rate, compression, recording mode, and how long footage must be retained.
Calculate storage from the recording plan
Eight cameras averaging 4 Mbps each need about 10.37 TB for 30 days of continuous video recording. At 2 Mbps per camera, the same example needs about 5.18 TB. These decimal-TB estimates exclude audio, filesystem overhead, reserved space and growth allowance. Resolution alone does not determine retention.
Decimal TB = camera count × average bitrate in Mbps × 1,000,000 × recording hours per day × 3,600 × days ÷ 8 ÷ 1,000,000,000,000.
For eight cameras at 4 Mbps recording 24 hours a day for 30 days: 8 × 4 × 0.0108 × 30 = 10.368 TB before allowance. For mixed cameras, calculate each bitrate group separately and add the results. Use measured average bitrate where available; do not assume event recording follows a fixed duty cycle.
Check the recorder's supported drives and usable capacity, allow for audio, overhead and reserve space, then verify retention with actual recordings. These examples are not a guarantee for a particular camera or recorder.
What changes storage demand
- Higher frame rates use more space.
- More outdoor motion can increase recording volume.
- Compression settings affect final retention days.
- Critical entrances may need higher resolution than low-risk zones.
Storage planning
Keep the footage for as long as you need it.
Match NVR channels and drive capacity to camera resolution, recording mode, retention days, and room for future cameras.