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VoIP codec bandwidth calculator
See how much bandwidth each call uses once packet headers are included — and how much your connection needs for all your concurrent calls.
Per call, each direction
87.2 kbps
All calls, each direction
872.0 kbps
Packets per second (per call)
50
Packet: 160 bytes voice + 40 bytes IP/UDP/RTP + 18 bytes Ethernet = 218 bytes.
Why calls use more than the codec rate
A codec's bitrate only counts the voice data. Every packet also carries 40 bytes of IP, UDP and RTP headers, plus Ethernet framing on a local network. With a 20 ms packet interval that is 50 packets per second, so G.711's 64 kbps of voice becomes about 87 kbps on the wire, in each direction.
Tips
- Bandwidth is per direction. A call needs the same amount up and down.
- Longer packet intervals cut header overhead but add delay. 20 ms is the common default.
- Leave headroom: plan for well under your line's real capacity, especially on upload.