Network Bandwidth Calculator

Sustained-bandwidth applications like continuous CCTV recording present a different network sizing challenge than typical internet usage, and understanding that difference is the key to why this simple multiplication — device count times per-device bitrate — is actually the right approach here, even though it would be an overly pessimistic way to size a network for most other kinds of traffic.

Most everyday internet usage is bursty rather than sustained: loading a web page consumes bandwidth in a short spike, then the connection sits mostly idle until the next page load or download; even video streaming from consumer services typically buffers ahead and doesn't require a perfectly continuous data rate at every instant. This burstiness is exactly why internet service providers can oversubscribe their infrastructure — selling more total nominal bandwidth to their customer base than the underlying infrastructure could support if every customer used their full rated bandwidth simultaneously — and get away with it in practice, because in normal usage patterns, not everyone is bursting at the same moment.

Continuous CCTV recording breaks this assumption entirely. A camera configured for constant-bitrate (CBR), 24/7 recording genuinely does consume its full rated bitrate continuously, every second, for as long as it's operating — there's no bursty, intermittent usage pattern to average out, because the camera is always transmitting video data at essentially the same rate. This means a network link carrying multiple such cameras needs genuine sustained capacity equal to the sum of all the cameras' individual bitrates, not some smaller 'typical usage' estimate that might work for bursty traffic — exactly the straightforward summation this calculator performs, without the more forgiving oversubscription assumptions that make sense for other kinds of network traffic.

This distinction is also exactly why wired Ethernet connections are strongly preferred over Wi-Fi for sustained CCTV bandwidth specifically, beyond Wi-Fi's general reliability concerns. Wi-Fi is fundamentally a shared medium — all devices on the same wireless network compete for the same available airtime, and a wireless access point's total real-world throughput is typically well below its advertised maximum rating, especially once multiple devices, interference, and distance from the access point are factored in. For bursty traffic, this shared, variable nature is often tolerable, since not every device needs peak throughput simultaneously. For sustained, continuous CCTV streams specifically, where every camera genuinely does need its full bitrate available at all times, Wi-Fi's variability and shared capacity make it a poor match — a wired connection, by contrast, provides genuinely dedicated, predictable bandwidth to each connected device, exactly matching what sustained streaming traffic actually requires.

For real-world network planning, the raw sum-of-bitrates figure this calculator produces is best treated as a floor rather than a target to design exactly to — protocol overhead (the additional data consumed by network packet headers, error checking, and occasional retransmissions) typically adds a meaningful percentage on top of the raw video payload bitrate, and running any network link consistently at its absolute rated maximum capacity leaves no margin for momentary spikes or unexpected additional load, which is exactly why the standard practice of adding 10-20% headroom beyond the calculated minimum exists — treating the raw calculation as a floor to build from, not a precise target to hit exactly.