If you’re considering VoIP phone service for your business, it’s important to use a VoIP speed test to determine if and how many phone lines your connection can handle.
Using the free VoIP speed test below you can find your bandwidth and latency, and we’ll explain exactly what this means for your VoIP capabilities.
VoIP Speed Test
How Many Phones Can My Internet Connection Support?
Look at the two numbers on your speed test: The Download Speed and Upload Speed, located on the top left and right, respectively.
Take whichever number is lower (typically the upload speed) – we’ll call this your bandwidth speed. Now match your bandwidth with the number in the chart below:
If you’re interested in replacing your internet service provider, check out our guide Best Business Internet Provider in Every US Market.
VoIP Speed Test: How To Do The Math
If you want to find the exact number of lines you can support, here’s how it works:
- First take your upload speed and multiply it by 1000. This is to convert it from Mbps to Kbps. For example, 11.99 Mbps = 11,990 Kbps. If your speed is already expressed in Kbps, leave it as is.
- Now divide this number by 445. This will tell you the recommended number of phone lines your connection can support. For example, 11,990 / 445 = 27 VoIP phone lines.
- To find the maximum number, take that same number and divide it by 100. This is how many phone lines you can support in a perfect world, if your connection speed were to be completely steady and if you weren’t using your internet for any other activities, like internet browsing or downloading.
Maximum vs. Recommended Number of Lines: What’s the Difference?
The number of VoIP lines you can support doesn’t just depend on your internet speed. It also depends on how much of your bandwidth is used up by other things, like internet browsing, email, online software, web-based POS systems, etc.
Our recommended number of lines takes into account these other browsing activities, as well as natural fluctuation of internet speed throughout the day.
The maximum number of lines you could support if your connection is used exclusively for VoIP, and your internet speed is consistent. Cable internet speeds tend to fluctuate, whereas newer fiber connections are more reliable. Learn more about connection types on our guide How to Set Up Internet for Your Business.
What Do The VoIP Speed Test Numbers Mean?
- Upload Speed – The upload speed which is shown in the upper right hand corner of the above test shows the upload capability of your connection, measured in megabits per second (Mbps). Because this number is typically lower than your download speed, this reflects the actual bandwidth available to your computer.
- Download Speed – Shown in the upper left hand corner of the VoIP speed test shows the download capability of your connection. It’s the maximum amount of data your connection can receive, measured in megabits per second (Mbps). As long as your upload speed is lower than your download speed, you can ignore this number. In the rare case where this number is higher, then this is your actual bandwidth.
- Ping – the amount of time it takes for your computer to communicate with a server. On a VoIP phone call, this constitutes the latency (or delay) between you and person you’re speaking with. Small delays aren’t noticeable, so as long as this number is below 100ms, you should be good to go.
What is Bandwidth?
Bandwidth is maximum rate at which your network can transfer data. It’s one of the key factors in the VoIP speed test since it determines how many concurrent phone calls your connection can handle.
Bandwidth is measured by your download and upload speed – the rate information travels to and from your computer. Whichever number is lower is your bandwidth. Because most consumers download much more than they upload, most internet service providers (ISPs) design the network to allow faster downloads than uploads. This is why your upload speed is probably lower than your download speed.
Now, each VoIP phone call typically requires 100 Kpbs up and down – or 1/10th a Mpbs. So if your upload speed is 10 Mpbs, you could theoretically handle up to 100 VoIP phone calls at once. The actual number, however, is closer to 10 or 20 calls. Here’s why:
Bandwidth (Upload Speed)
Bandwidth Fluctuation (Subtract)
Internet Browsing Activity (Subtract)
Bandwidth Available for VoIP
Maximum Number Of Concurrent Phone Calls
- 105 Kbps
- 250 Kbps (1 user)
1 phone call
- 210 Kbps
- 500 Kbps (2 users)
2 phone concurrent phone calls.
- 1.05 Mbps
- 2.75 Mbps (11 users)
11 concurrent phone calls
- 2.1 Mpbs
- 5.5 Mbps (22 users)
22 concurrent phone calls
- 16.75 Mbps (67 users)
67 concurrent phone calls.
There’s two main reasons why you need to give some leeway when measuring bandwidth. For one, internet speeds fluctuate throughout the day. When more subscribers in your local area are using the internet, speeds can vary up to 21 percent, according to one study of broadband internet connections.
Another factor is web browsing. if you’re using the same internet connection to check email, stream videos, or run web applications, your VoIP lines will have to compete for bandwidth. Heavy internet activity (Email + Youtube + Spotify) takes about 1 Mbps download per user. Fortunately they don’t require nearly as much upload bandwidth – the typically more important factor for VoIP phone calls. We’ll say you lose just about 0.25 Mbps per user for internet browsing. The exception is if you do a lot of upload-intensive work, like sharing videos/graphics or collaborating on files. Then this number could be a lot higher.
The other number you’ll see on the speed test is Ping. This measures the latency (or delay) between your computer and the network you’re connecting to, so it translates to the delay you’ll hear when speaking on the phone. Anything below 100ms is a safe number. Here’s why:
Delays typically aren’t noticeable on the phone unless they’re over 250 milliseconds (ms). So if your ping time is below 100ms and the person you’re speaking with has a ping time below 100ms, you should be good to go. The reason we leave an extra 50ms for leeway is because of the delay the system takes to encode and decode the voice.
Improve a Bad Connection by Allocating Bandwidth
If you have a small office, most broadband connections will give you more than enough bandwidth for VoIP calls. With an average upload speed over 6 Mbps in the US, a typical connection can handle 12+ lines no problem.
On the other hand, if you need more than 12 lines and/or if your connection is significantly lower, your VoIP calls may be in trouble. Fortunately, there’s still a hack that can improve your call qualities, even with a low bandwidth:
Bandwidth allocation is when you specify which internet activities get priority on your network. In other words, you can allocate a certain percentage of your bandwidth to VoIP. Then, when your network gets strained, it will slow other activities (like internet browsing, download/uploading files) before it slows your calls.
To set up bandwidth allocation, you need to adjust the Quality of Service (QoS) settings on your router. You can typically do this online by going to the website of your router provider (i.e. Netgear, Linksys, D-Link, Cisco) and logging into your control panel. LaptopMag has a good guide on setting this up with a Netgear router. To find one for your own system, just search “[Your Router] Bandwidth Allocation.”
Does My Choice of VoIP Provider Affect Call Quality?
Yes. VoIP providers differ in how they handle your calls, such as how they encode your signal. One of the biggest factors that can affect your call quality, however, is how many data centers they operate. Smaller companies who just have 1 data center, for example, will be prone to more issues when their network is overrun. By contrast, larger companies can offer more reliable service by spreading their service out across locations.
This is why we recommend Nextiva. As one of the largest VoIP providers with several data centers, users routinely rank their call service quality above the competition.
The Bottom Line
Most broadband connections are well over the requirements to support 1 to 10 concurrent VoIP phone calls. With a high speed business connection, that number can be much higher. Just bear in mind that VoIP calls have to compete with other upload-intensive internet activities. So if you do things like collaborate on graphics or just upload a lot of files, you’ll have to factor that into your VoIP capabilities.
VoIP call quality is similar to traditional phone service, provided you have the appropriate internet connection. If you are looking for a high quality VoIP service provider we recommend Nextiva, and you can read our full VoIP provider comparison guide here.