Free tool
NDI, SDVoE and Dante bandwidth calculator
Check a switch before you spec it. Pick the stream type, set how many you are sending, and see the total bandwidth, what percentage of the uplink it eats, and how many streams that uplink really carries. Free, and nothing leaves your browser.
Total bandwidth
240 Mbps
0.24 Gbps
Uplink utilisation
2.4 %
Streams the 10 GbE uplink carries
500
Comfortable. The headroom absorbs encoder bursts, multicast flooding, and control traffic.
Payload only. Ethernet framing, IGMP and PTP traffic, and encoder peaks add a few percent on top. Estimate for sizing, not a substitute for the vendor bandwidth table.
The switch is the matrix now, so size it like one
Once video rides Ethernet, the port count and the uplink speed decide what the system can do. A rack of NDI HX3 encoders is happy on a gigabit trunk; the same rack running NDI High Bandwidth needs ten times the pipe. Getting that wrong shows up late, as tearing and dropped frames on site, when the switch is already installed.
How the maths works
- Total = bitrate per stream × number of streams, all in Mbps.
- Utilisation = total divided by the uplink rate, so 4 Gbps on a 10 GbE trunk is 40 percent.
- Stay under 70 percent sustained: encoder bursts and multicast overhead need the rest.
Figures are payload only, and vendor bandwidth tables beat any generic number. New to the topic? Start with AV over IP. Designing the whole system? Avitly keeps the endpoint count on the plan and the switch on the parts list in step, so the stream count you calculate here is the one you actually install.
Common questions
How much bandwidth does an NDI stream actually use?
NDI High Bandwidth at 1080p60 sits around 125 Mbps per stream, and a 4K60 feed can pass 250 Mbps. NDI HX3 is far lighter, roughly 20 Mbps at 1080p60, because it uses long-GOP compression instead of the near-intraframe codec. The exact number moves with scene complexity: a static slide costs less than a handheld camera panning across a crowd, so size for the busy case, not the average.
Why does SDVoE need 10 GbE?
SDVoE sends visually lossless 4K60 with about one frame of latency, which costs roughly 9 to 10 Gbps per stream. That is a full 10 GbE port per endpoint by design: the tradeoff is that you get matrix-like switching behaviour and near zero latency. If 10 GbE per endpoint is out of budget, a compressed transport such as NDI HX3, JPEG XS at lower rates, or an H.265 platform is the realistic alternative.
How much headroom should I leave on an uplink?
Keep sustained load under about 70 percent of the link rate. Video encoders are bursty, so a stream averaging 20 Mbps can peak well above that for short windows, and those peaks are what fill switch buffers and cause dropped frames. On top of the payload you carry Ethernet framing overhead, IGMP membership traffic, PTP clock messages, and any control or management traffic riding the same link.
Does multicast reduce the bandwidth I need?
On the uplink, yes: one multicast stream crosses a trunk once no matter how many receivers subscribe, whereas unicast sends a separate copy per receiver. That only holds if IGMP snooping and a querier are configured correctly. Without them the switch floods multicast to every port and you get the worst of both, so every endpoint sees every stream. Configure snooping before you rely on the saving.
Should audio and video share the same network?
They can, and on modern switches they usually do, but Dante and other audio transports need PTP clock accuracy and consistent low latency far more than they need raw throughput. Eight channels at 48 kHz is only about 12 Mbps. Give audio its own VLAN with QoS, mark PTP correctly, and avoid putting it behind a link that video regularly saturates. Separation by VLAN is cheaper and more flexible than separation by cable.
Do these numbers cover the access ports too?
This calculator sizes the aggregate, which is normally the uplink or trunk between switches. Access ports matter separately: one SDVoE endpoint needs a 10 GbE access port regardless of the total, and an NDI High Bandwidth encoder is uncomfortable on a shared 1 GbE port with other traffic. Check both, the per-endpoint port speed and the aggregate the trunk has to carry.
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