How to Estimate Bandwidth Needs for Your Customers


When it works, you never hear a peep about it. But when bandwidth problems start to plague a residential or business customer, you’re probably the next person being called right beside the ISP themselves. An interesting piece on this dilemma recently showed up on Ars Technica which rounded out the bandwidth debate among technicians pretty well. Insight from various tech workers is sampled, and they all gladly describe their complacency or (more commonly) displeasure with internet speed being delivered to their workplace. What constitutes “enough” bandwidth one may ask?

That precise question is a tough one to answer. I’m fairly certain that a decent majority of techs reading this would say that “no news is good news” when it comes to a sufficient WAN connection for a given customer. For those of us in the States, this should come as no surprise, since we rank a paltry 26th in a recently released study of global average connection speeds. According to the study, funded by media distribution giant Pando Networks, the typical “broadband” connection in the USA stands at around 616Kbps. That’s only roughly 11 times faster than the best 56K connections of yesteryear. Even in the age of Comcast offering low income families access to 1.5Mbps service for $10/month, the majority of Americans probably have no clue what a “Comcastic” internet connection is.

What does a typical home or office WAN connection need in terms of bandwidth anyway? If there is a silver bullet answer for this question, I’d love to know about it. The way we consume the modern internet pipeline is vastly different from what we used to do back in the late ’90s. AOL was used by a good majority of Americans, Yahoo was still the hottest thing since sliced bread, and email was still a novel nicety, not necessarily a necessity yet.

Streaming music and video, constant social media, and Web 2.0 (er, now Web 3.0 perhaps) have transformed the web from a text driven experience to a full blown multimedia haven. Not to mention how rapidly new age cloud-based services are pushing the envelope on bandwidth needs. Google Apps, Office 365, and Salesforce are all excellent platforms – as long as you have the juice to supply them appropriately.

While the discussion doesn’t come up too often for residential customers of my company FireLogic, business offices are increasingly turning their sights onto Google Apps and Office 365 for email and collaboration platforms. But don’t count the residential user out by a long shot. They’re sucking down bandwidth quite heavily between Netflix, Pandora, and all of the online game services from PlayStation Network to Xbox Live. Estimating based on professional experience is how I handle a good portion of customers who inquire about what they need for bandwidth. But if you don’t have that background to be able to shoot from the hip with a good estimate, luckily I’ve compiled some decent sources to help out. Here are my best guidelines for recommending bandwidth needs for your customers.

Residential Customers: A Fairly Easy Crowd to Satisfy

Business bandwidth needs can get complex pretty quickly, so let’s start off with the easier clients. Residential customers have pretty straightforward needs most of the time (outside of those power users who need to stand out.) The things most residential customers care about (in general; not conclusive by any means):

  • Regular internet browsing
  • Social media
  • Email & instant messaging
  • Streaming video, music
  • Online gaming (i.e. Xbox Live)
  • Smartphone connectivity over Wi-Fi

The above list doesn’t represent anything too crazy, and is generally what I encounter onsite. But while bandwidth needs for a 1998-era internet were quite forgiving, today we have to account for many more variables such as:

  • How much streaming video is being accessed on a daily basis?
  • How many people are downloading music or streaming Pandora?
  • How many simultaneous users will be on at peak hours?
  • Are there multiple online gamers in the home?
  • Is VOIP in the form of Vonage or similar being used?

All of these variables need to be taken into account to avoid the snags commonly experienced by an underwhelming WAN connection. While there is no great formula for determining residential WAN overhead, has a pretty spot-on table showing what speed levels are accurate depending on general needs. I’ll go a step further to qualify the table and say that in general, a 2-4 person family without heavy gamers or media streamers can get away with the 3-4Mbps connection level. Add on a few more family members or heavy gamers/media types, and I’d likely look towards a 5-9Mbps or higher connection. Reference the table on their site to see where an average residence may fall depending on usage scenario.

Business Customers: Bandwidth Hungry and Tough to Predict

The types of businesses I am referring to in this quick guide are home offices, small businesses and midsize businesses. Enterprise level internet setups follow similar parameters but generally have professionals that gauge needs with a lot more accuracy. What we’re after here is more of a guiding principle for how to evaluate what an office would likely need in bandwidth. And don’t think that getting this estimation right on the first try is always a piece of cake; many times, you may have to adjust a bandwidth subscription level depending on real life usage testing.

Offices represent a different kind of beast in comparison to residential internet customers. Social media and streaming video are still bandwidth hogs, but in most cases those can and should be controlled to certain degrees. Today’s office workers are embedded heavily in some of the following internet-centric tasks:

  • Email (and lots of it)
  • Cloud services (hosted email, hosted accounting, hosted CRM, etc)
  • Online banking
  • Online research
  • VOIP in place of PBX phone systems
  • Downloading/uploading large files
  • Online backup

While resources are still scant on how to properly estimate this with 100% accuracy, I’ve dug up a few online outlets that offer documentation. Microsoft released an overly technical brief on the matter of bandwidth estimation that is available online, but to be honest, save yourself the headache and check out a streamlined alternative that summarized the theories. Since both websites focus on email “consumption” as the basis for their calculations, I’m going to extend the scope and bring in some real world considerations:

  • Is VOIP in use at the office, and how many users are on it?
  • How much email is being sent & received per day per user?
  • Is cloud email like Google Apps being used?
  • Are other cloud services like Salesforce or Quickbooks Online used?
  • What is the office culture on streaming media usage like?
  • Is content filtering an option, or off the table?
  • Are any public facing web servers hosted internally?
  • Are social media outlets open for usage or banned?
  • Does online backup (i.e. CrashPlan) play a role in core backup needs?

The above items of interest all play key roles in how much bandwidth a company may require. The recommended site I linked to provides a simple way to calculate bandwidth needs in the form of:

N x T = BN
umbers of users (x) Traffic estimate based on usage weight = Bandwidth Needed

Some decent examples on the page above provide insight as to what they consider “light” and “medium” and “heavy” users. However, seeing as weights were considered only dependent on email needs, they are deceiving for what the modern office worker slurps from the fat pipe. I’d be as liberal to say that the following user weight groups are appropriate today:

  • Light user: 50Kbps
  • Medium user: 80Kbps
  • Heavy user: 120 Kbps

So for example, an office may have a mixture of users. This hypothetical company is comprised of 20 users. 5 heavy users who are the big whigs, 5 medium users who are the admin assistants and related positions. The remaining 10 users are light office workers who only use email. We would setup our estimate calculation in the following manner:

  • 5 (heavy users) x 120 (Kbps usage weight) = 600Kbps
  • 5 (medium users) x 80 (Kbps usage weight) = 400Kbps
  • 10 (light users) x 50 (Kbps usage weight) = 500Kbps
  • Bandwidth Needed = 1500Kbps or 1.5Mbps

The above numbers may even be a tad conservative. So many factors could inflate bandwidth needs like the number of VOIP connections being used at a time to how many large emails are being sent and received in chunks of time. Issues with bandwidth usage spikes are frequent in office settings, where peak usage may be horrendous during mid-day hours and level off in the morning and afternoon. Real life situations vary from customer to customer so don’t hold my generalities as rule of thumb../;

You may even want to multiply my usage weights above by a degree if you feel that they are too conservative. There is no exact science to these calculations. Network baselining may provide better insight into usage but even then professional judgement is key. And for those that want a simpler way to approach estimation of bandwidth, put together a simple calculator that can plug and chug variables and spit out a figure. It may not be a bad idea to average out what both listed routes above provide for estimates. Second opinions are insightful with such imperfect science.

Keep in mind that bandwidth estimation for customers is tough to perfect but becoming ever moreso necessary. The white lie of “enough bandwidth” is just that: most of the time, customers need to settle on a happy medium of cost vs needs. Your job as the technician is to properly consult them on their needs and recommend quality, cost effective solutions.

Post your tips and comments on bandwidth estimation below – we’d love to hear about them!

Derrick Wlodarz

About the Author

Derrick Wlodarz
More articles by me...
Derrick Wlodarz is an IT Specialist that owns Park Ridge, IL (USA) based technology consulting & service company FireLogic, with over 8+ years of IT experience in the private and public sectors. He holds numerous technical credentials from Microsoft, Google, and CompTIA and specializes in consulting customers on growing hot technologies such as Office 365, Google Apps, cloud hosted VoIP, among others. Derrick is an active member of CompTIA's Subject Matter Expert Technical Advisory Council that shapes the future of CompTIA exams across the world. You can reach him directly at

Comments (8)

  • Matt D. says:

    Another good one Derrick! Have you or anyone else reading this ever used a piece of software or hardware to assess the network load going out to the ISP? I have always wondered if this would be helpful, but never had the opportunity to use such a method.

  • Brad says:

    Great article, although I’d say it’s a bit dangerous to suggest a 1.5Mbit connection for ANY business with more than 2 or 3 users, let alone one with 20. A bit more than a tad conservative, lol.

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  • Derrick Wlodarz says:


    I know people won’t agree with the figures I may have used, but there is no single answer sadly for what constitutes various “usage” levels based on user types. My numbers could have definitely been higher though, I won’t deny that :-)

  • Paul B. says:

    Another way to come at this is to maximize the existing connection by prioritizing and balancing the load. This usually is not hard to do in the router, where less important machines can be relegated to smaller bandwidth, so their needs don’t eat into the needs of machines doing more important functions.

    Also, the local server can be used as a proxy to store downloads for everyone’s local consumption. Windows and application updates, as well as individual large downloads, can be downloaded manually and stored on the LAN, where they can be accessed locally. This will generally be faster, and at the same time not cost the INet connection anything.

    And of course, routine jobs such as cloud backup and inter-office sync can be scheduled for the off hours.

    • Tony_Scarpelli says:

      I am plagued with slow internet availability and high demand in my Computer Fix Store. I researched whether a cache server would help and since most of what I want cached are ftp files I couldn’t figure an automated way to do it.

      We then experimented with manually saving the FTP’s but with that comes management, organization, identification which proved too difficult to enforce. So we put up with a slow internet and slow repair rate.

      I would love to hear if anyone can solve this problem.

  • chuck817 says:

    There is still more for those who have been aground that your equations didn’t put in
    know what the ISP terminology means (in other words lawyer ease)

    for instance the words “UP TO” plus other factors such as

    does your ISP put a cap on bandwidth or throttle bandwidth during peek usage hours
    does your ISP put a cap on bandwidth or throttle bandwidth streaming or social media during peak hours
    what are the peak hours in your area?

    but like I said the big thing you must watch out for is the word usage “UP TO”
    meaning that you could get up to xx.xx Mbps during off peak hours if the method of communication you choose isn’t being throttle at the present time

    to ensure that a client is getting the connection speed that they want i would take your final figures and multiply them by 10 to get a decent connection speed

  • Mike Smith says:

    Guestimating bandwidth requirements for small offices is really a no brainer these days. There are basically 2 choices; cheap broadband and expensive T1s, copper over ethernet, fibre etc.
    In the broadband case you suffer at the hand of fate and your broadband modem may choke under too many DNS requests, or other such calamities.
    In the case of the expensive “real” business class, your client purchases what they can afford, and then deals with the speed issues.
    The understanding is that it will never be enough.
    Your actual goal should be to gain insight into the network utilization and recomend strategies to mitigate slowness, understanding that if even you have 100Mb service, your client will still saturate it.
    In order to do that, you need to watch the traffic and build reports that show exactly what is going on, and then you can recomend strategies to handle it.
    Find a device that you can slip into their network to monitor and report usage patterns.
    Solving the bandwith utilization problems I guess would be broken down to QoS and caching. Both are not inexpensive; either in terms of money for the device or money for your time. Obviously if your client is on the serving side, and serving the same content (audio files, images, video, large documents etc.), you may want to consider hosting those file outside the clients network. Your research will tell you what to do for each client.
    Next have a look at WAN accelerators. Bluecoat WAN accelerators and Riverbed WAN accelerators are about 7,000.00 or more, and do a fine job of caching CIFS, Web, accelerating various network protocols, and more. Cost average it over a few years, and it’s actually reasonable, like 200.00 a month over 3 years. (Cheaper than a T1 where I am.)
    The more technical among you can try and roll your own with trafficsqueezer or Silver Peak, or just a simple squid proxy.
    Commercial firewalls like Astaro have a caching FTP proxy built in among other things. Remember though, with with the added complexity comes added work.
    For example, does the caching service require tweaks to make sites like netflix work. Never mind what should or shoulnd’t be used on an office network. When the boss can’t catch up on his Lillyhammer, you are the one who has to figure out why.
    So do a bunch of research, ask your vendors for advice on accelerators, read a bunch of manuals, and ask for demo units, and ask for deals. Test them at home and at the shop.
    Then install your chosen solutions and let the client run with them for a week or two. Turn them off and ask if your client notices. I think they will, and I think they will like it.