How much internet bandwidth does a VoIP call need?
Planning a calling team? See how much bandwidth each VoIP call uses, what matters more than speed and how to size your internet.
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People often worry that VoIP needs a fast connection. In practice, a single call uses very little data. What matters most is that the connection is steady, with low delay and few lost packets.
How much bandwidth does one call use?
A standard VoIP call uses roughly 80 to 100 kbps in each direction, and some modern audio formats use less. That is tiny compared with a video meeting.
| Simultaneous calls | Approximate bandwidth each way |
|---|---|
| 1 | 100 kbps |
| 5 | 0.5 Mbps |
| 10 | 1 Mbps |
| 25 | 2.5 Mbps |
Add a safety margin of at least 50% and remember that other things on your network, such as video and downloads, use bandwidth too.
What matters more than speed
- Latency: the delay in the connection. Under about 150 milliseconds one way feels natural.
- Jitter: variation in delay. Keep it low, ideally under about 30 milliseconds.
- Packet loss: lost data. Aim for under 1%.
How to size your internet
- Count the most calls you will have at the same time.
- Multiply by about 0.1 Mbps, then add a buffer.
- Check that your upload speed is enough, not only download.
- Test during your busiest hours.
Tips for a steady connection
- Use a wired connection where you can.
- Keep calling devices away from heavy downloads.
- Restart the router if quality drops.
- Use a mobile hotspot as a backup.
See Dialsyx's system requirements and our guide to fixing VoIP call quality problems.
A sizing example
A team of eight agents who all make calls at the same time needs roughly 0.8 Mbps of upload and download for voice. Add 50% for headroom and you get about 1.2 Mbps. If the office also streams video meetings and large downloads, plan for much more or separate those uses. Most modern broadband connections are well above this.
What eats your bandwidth
- Video calls and meetings.
- Cloud backups and software updates.
- Streaming music or video.
- Large file uploads.
How to protect call quality
- Schedule large uploads and updates outside calling hours.
- Use a router that lets you prioritise voice traffic, if available.
- Keep calling computers on a wired connection.
- Test again whenever the team grows.
Frequently asked questions
Do I need fibre for VoIP?
No. A steady broadband connection is usually enough for small teams.
Is Wi-Fi okay for calls?
A strong signal works, but wired is more reliable.
How do I test my connection?
Run a speed test and make test calls at busy times.
Does video need more bandwidth?
Yes, much more than voice.
We build business calling for teams in the USA, Canada, the UK, Australia and Japan, with a browser phone and a built-in CRM. About Dialsyx
