How to Calculate the Bandwidth Needed for a Site

Before purchasing a web hosting company, you need to take a lot of factors into consideration, among which the bandwidth calculation is the most challenging one.

Bandwidth refers to the amount of data transferred from your web host’s server to your visitors’ computer over a certain period of time. Unlike disk storage which can be controlled by deleting content like large images or videos, bandwidth requires careful calculation because your website might be shut down in the middle of the month when a lot of visitors have visited you or downloaded large files from your site.

In fact, most web hosting companies offer a variety of bandwidth options in their plans, so you can choose the right amount with which you don’t need to pay for more than you need, or deal with the penalty for going over your allotted amount.

But how do you determine the amount of bandwidth you are going to need? Our editors have answered the question in the following parts.

How Much Bandwidth Is Needed?

In fact, calculating the bandwidth needed is pretty easy. It only requires you to record some data of your website’s daily activities and do a math problem.

Estimate the average size of your web pages in kilobytes (KB).

Normally, a plain and simple webpage is about 200KB in size. But as you need to include some images, widgets and even multi-media components, the page size cannot be estimated precisely.

Here, we highly recommend you to use the Pingdom Website Speed Test Tool. You just need to find a webpage that is much similar to your expected page, and then, test its speed using this special tool. In the resulting bracket, you can know its page size in either KB or MB. And the number can be used as your estimated page size.

Estimate the average number of people you expect to visit your website each day.

For a new website, the daily visitors might be ranging from 100 to 400 for the initial 6 months. If you want to own an e-commerce site, the number can be double or even triple.

Estimate the average number of web pages you expect a person to view.

This depends on how many webpages you want to create. If your expected page number is 20, then your page views per person need to be calculated as 20. Just assume that a visitor will take a look at all your webpages.

These simple formula for calculating bandwidth is very straightforward, but do not forget to calculate all the sites on the server if you have multiple websites hosted on one account.

Consider Extra Bandwidth Needed

In fact, this result is just an estimate, and it is important to understand the distinction between theoretical calculation and real-world results.

For instance, if you have a website with 45KB page size, 1000 site visitors every day, and 4 page views each visitor, then you will theoretically need about 4.5 GB of bandwidth per month.

However, this amount of bandwidth is not enough in practice because of the following cases:

File Downloads

If you allow visitors to download files from your website, then you need some extra bandwidth for the download process. Thus, calculate the average size of files that are downloaded from your site and the average number of downloads you expect to occur on your site, and multiple the results with your theoretical amount of bandwidth.


If you are planning to post some videos, music, Flash animations and any other multimedia on your website, then you may use more bandwidth than only post HTML text-only contents and images. For instance, if you have a 200MB video file available for download, then the estimated 4.5GB of bandwidth would only allow you to offer 22.5 downloads.

Growing Traffic

If your website is of high quality with interesting content, then there must be more and more visitors become your loyal readers, which means the average number of daily visitors, page views, and daily downloads you have previously estimated will increase significantly, and the amount of bandwidth needed will also increase accordingly. In a word, you need to plan for the future and give your website a room to grow.

Layout Changes

If you are not satisfied with how your website looks like, then you may change its layout. But remember that this practice may increase the size of your web page, thus resulting in more usage of bandwidth.


In fact, the bandwidth is just like a highway, if you are the only car on a highway, then you can travel very quickly. But if there are too many cars available, you will be stuck in the middle and travel very slowly, for all of the lanes are being used up. Therefore, calculating the bandwidth and plan ahead is pretty important.

Last but not the least, when it comes to choosing the right web hosting company, there’re many more factors needed to be concerned other than just bandwidth, such as price, speed, reliability and support. Here, we highly recommend the following great options.

Rick Hammond

I'm a marketing consultant by trade and also own a portfolio of over 20 websites. Over the years I have tested most of the well know hosting companies for my sites and therefore can give insight into which are good and which are not from my personal experiences.

Related Articles