Network planning
VoIP bandwidth calculator
Enter concurrent calls and select a codec to get exact bandwidth requirements including Ethernet, IP, UDP, and RTP overhead. Essential for call-center WAN sizing and QoS planning.
64 kbps, μ-law, North America
Results
Per call (full duplex)
512.0Kbps
Total (50 calls)
25.60Mbps
25600 Kbps
| Layer | Kbps |
|---|---|
| RTP payload (G.711u (PCMU)) | 64.0 |
| RTP header (12 B) | 64.00 |
| UDP header (8 B) | 64.00 |
| IP header (20 B) | 64.00 |
| Per direction | 256.0 |
How it works
Three steps to results
- 01
Set concurrent calls
Enter the peak number of simultaneous calls your trunk or WAN link must support. The calculator multiplies per-call bandwidth by concurrency for total throughput.
- 02
Pick a codec
Choose G.711a/u (64 kbps), G.729 (8 kbps), G.722 (64 kbps), Opus (configurable), or GSM. Each codec has a different payload size that drives bandwidth consumption.
- 03
Read the breakdown
See per-call and total bandwidth in Kbps and Mbps with a layer-by-layer breakdown: RTP payload, UDP, IP, and optional Ethernet L2 overhead for both directions.
FAQ
Frequently asked questions
Common questions about this tool and how it fits into your VoIP security workflow.
Contact support →G.729 uses an 8 kbps RTP payload. With IP (20 bytes), UDP (8 bytes), and RTP (12 bytes) headers, each direction is roughly 31.2 kbps. A full-duplex call needs about 62.4 kbps before Ethernet overhead.
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