NVR Bandwidth Calculator
Add up the total network bandwidth your IP cameras push to an NVR, and check it against your switch or NIC capacity with headroom to spare.
How it works
Total = cameras × bitrate · Usable = link × (1 − headroom%) · Utilization = total ÷ link · Max cameras = usable ÷ bitrate
Every IP camera streams its full bitrate to the NVR continuously, so the load on the recorder’s network port is simply the sum of all camera bitrates. A single Gigabit link handles a lot of 1080p cameras but far fewer high-bitrate 4K streams, and you should never plan to fill a link to 100% — leaving headroom absorbs bursts, keyframes and management traffic. If the total exceeds your usable capacity, lower bitrates, spread cameras across multiple switch uplinks, or step up to a multi-gig NVR port.
Worked example
Eight cameras at 6 Mbps push 48 Mbps to the NVR. On a 1,000 Mbps (Gigabit) uplink that is under 5% utilization, and keeping 20% headroom leaves 800 Mbps usable — enough for well over 100 such cameras before the link becomes the bottleneck.
Frequently asked questions
Is NVR bandwidth the same as internet upload?
No. This is local traffic between the cameras and the NVR on your LAN, which stays inside your network. Remote viewing over the internet uses your upload bandwidth separately and is usually a single re-streamed feed, far smaller than the raw camera total.
Why leave headroom instead of using the full link?
Camera bitrates spike on scene changes and keyframes above their average, and the link also carries discovery, time sync and playback traffic. Running a link near 100% invites dropped frames, so 20–30% headroom keeps recording reliable.
What limits cameras per NVR — bandwidth or ports?
Both. PoE NVRs cap you at their physical port count and PoE power budget, while the recording throughput and disk write speed cap the total bitrate. This calculator focuses on the network link; check the NVR’s rated incoming bandwidth too.
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This calculator is for educational purposes. Double-check important results before acting on them.