What Internet Speed Do You Need for VoIP?

Because VoIP carries your calls over the internet, the quality of your connection directly affects the quality of your calls. The reassuring news is that VoIP needs surprisingly little bandwidth - what matters more is stability. Here's what you actually need.

How much bandwidth does a VoIP call use?

Each simultaneous VoIP call uses roughly 85-100 kbps (kilobits per second) in each direction. That's tiny by modern standards. To estimate your needs, multiply by the number of calls you expect at once:

• 5 concurrent calls ≈ around 0.5 Mbps
• 10 concurrent calls ≈ around 1 Mbps
• 20 concurrent calls ≈ around 2 Mbps

Even a modest business broadband connection has far more than this. The headline "speed" is rarely the problem.

Speed isn't everything - these matter more

For clear calls, three other factors matter more than raw download speed:

• Latency - the delay for data to travel. High latency causes awkward "talking over each other" delays. You want this low and consistent.
• Jitter - variation in that delay. High jitter makes audio choppy or robotic.
• Packet loss - data that goes missing en route, causing dropouts and garbled speech.

A connection can have a fast headline speed but still deliver poor calls if latency, jitter or packet loss are bad. If you're hearing problems, our guide to common VoIP problems and fixes will help.

Don't forget the upload

Home and business broadband often has much slower upload than download. Since your voice has to travel out, upload speed matters just as much for VoIP. Fibre connections with healthy upload speeds are ideal.

Getting it right

• Use a wired connection for desk phones where possible - Wi-Fi adds jitter.
• Prioritise voice traffic with Quality of Service (QoS) on your router so calls take priority over downloads.
• Have enough headroom so a big file upload doesn't starve your calls.
• Consider a dedicated or business-grade connection for call-heavy teams.

A good provider will assess your connection before you switch and flag anything that needs improving - one of the things to look for when choosing a provider.

The bottom line

VoIP doesn't demand huge bandwidth, but it does want a stable connection with low latency and a decent upload speed. Get those right - ideally on fibre, with QoS enabled - and your calls will be crystal clear. Want your connection assessed before you switch? Request a callback or explore our Cloud Telephony service.