Quick path
Use the Streaming Bandwidth Calculator when you already know the configured bitrate for each camera, encoder, or livestream profile. Enter main stream bitrate, sub stream bitrate, stream count, concurrent pulls, duration, overhead, and margin to get total Mbps and traffic.
Core formula
For each stream profile, add video bitrate and audio bitrate. Multiply that number by how many streams exist and how many clients or servers pull each stream. After adding main and sub stream loads together, apply protocol overhead and safety margin.
Traffic conversion is linear: GB = Mbps * seconds / 8 / 1000. A continuous 1 Mbps
stream is about 0.45 GB per hour before extra margin.
Main stream and sub stream
A common CCTV or NVR system records main streams but serves sub streams for mobile preview or multi-camera grids. Do not assume only one of them counts. If both paths are active, both consume bandwidth.
Where to count concurrency
Count the network segment you are sizing. If one media server pulls each camera once and then redistributes to viewers, camera uplink load is different from server egress load. Direct camera pulls from many clients are more expensive on the camera-side network.
When bitrate is unknown
You can estimate from resolution, frame rate, and bits per pixel per frame, but this is a planning shortcut. Actual bandwidth changes with codec, motion, noise, night scenes, GOP length, encoder preset, compression setting, and bitrate control mode.
Production checks
- Measure average and peak bitrate on representative scenes, not only a quiet sample.
- Include audio streams, protocol overhead, TLS, retransmission, and packet loss margin.
- Check whether the bottleneck is camera uplink, NVR ingress, media-server egress, or viewer download.
- Leave headroom for temporary VBR spikes and future channel expansion.
Next step
Open the Streaming Bandwidth Calculator, start with configured bitrate, then compare the result with measured network traffic before buying bandwidth or sizing an NVR.