How the calculation works
For each row of identical cameras:
- Bitrate per camera = the bitrate you enter, or the planning default for the resolution × the codec factor × frame rate ÷ 30
- Stream = cameras × bitrate, in Mbps
- Storage per day = stream × recording share × 86,400 seconds ÷ 8, in bytes
Then:
- Network bandwidth into the recorder = the sum of every camera’s stream. It assumes every camera streams all the time, which is how most recorders do live view and motion detection.
- Storage = storage per day × retention days × (1 + overhead %), in decimal TB (1012 bytes), the unit drives are sold in. The binary figure (TiB) is shown too.
Planning defaults (used when the bitrate is blank):
| Resolution | H.264 at 30 fps | H.265 at 30 fps |
|---|---|---|
| 1 MP (720p) | 2 Mbps | 1.2 Mbps |
| 2 MP (1080p) | 4 Mbps | 2.4 Mbps |
| 4 MP (1440p) | 8 Mbps | 4.8 Mbps |
| 5 MP | 10 Mbps | 6 Mbps |
| 8 MP (4K) | 16 Mbps | 9.6 Mbps |
- The H.264 figures for 1, 2 and 4 MP are from Reolink’s IP camera bandwidth guide (read October 2026). Reolink doesn’t state a frame rate; the calculator treats them as 30 fps, the top of the usual range. 5 and 8 MP extend the same 2 Mbps per megapixel.
- H.265 is 60% of H.264, the middle of the “roughly 30–50% less bitrate” in Video Experts Group’s recommended bitrate settings (read October 2026). That page lists lower bitrates for moderate-motion scenes (1.5 to 2.5 Mbps for 1080p H.264), so these defaults sit at the conservative end.
- Scaling by frame rate is a simplification: modern codecs send mostly the changes between frames, so halving the frame rate usually cuts the bitrate by somewhat less than half.
All of these are planning assumptions. Scene activity, lighting, night mode, quality settings and smart-codec features change bitrates a lot; the bitrate your cameras report is better than any default.
Worked example
16 cameras kept for 30 days: 12 at 2 MP (1080p) on H.265 at 15 fps recording continuously, and 4 at 8 MP (4K) on H.265 at 15 fps recording on motion about 40% of the time.
| Cameras | Bitrate each | Stream | Storage a day |
|---|---|---|---|
| 12 × 2 MP, continuous | 4 × 0.6 × 15/30 = 1.2 Mbps | 14.4 Mbps | 155.5 GB |
| 4 × 8 MP, 40% recording | 16 × 0.6 × 15/30 = 4.8 Mbps | 19.2 Mbps | 82.9 GB |
| Total | 33.6 Mbps | 238.5 GB |
Over 30 days that is 0.238464 TB × 30 = 7.15 TB (6.51 TiB). With 20% added for overhead and free space, plan for 8.58 TB of usable space, before RAID.
The recorder’s network link carries 33.6 Mbps from the cameras around the clock, whatever the recording schedule. Remote viewing and cloud upload are on top of that.
Recorder or cloud
The storage figure applies to either. For an on-premises recorder, add the RAID overhead and leave room for more cameras. For cloud video (VSaaS), the upload is the issue: a camera that records to the cloud continuously sends its whole stream over the internet connection, so check the upload against the office bandwidth calculator. Cameras also need PoE: the PoE budget calculator checks the switch.
