Bandwidth Explained

Hosting's Most Misunderstood Phrase

Updated - 06/06/2003

Bandwidth describes the amount of data a network can transport in a certain period of time. In other words, bandwidth is a capacity for rate of data transfer.

Bandwidth is usually expressed in bits per second, as follows:

1 bit (b) is a ZERO "0" or a ONE "1" and that is single binary digit of information
1 byte (B) is 8 bits (b)
1 Kilobyte (KB) is 1,024 bytes (or 1,000 bytes)
1 Megabyte (MB) is 1,048,576 bytes (or 1,000 KB)
1 Gigabyte (GB) is 1,073,741,824 bytes (or 1,000 MB)
1 Terabyte (TB) is 1,099,511,627,776 bytes (or 1,000 GB)

Every time you use a computer to communicate with another computer via the Internet, you are moving bits of information through various Internet network providers. Some of your Internet activities, such as sending email, use very little bandwidth, while other activities, such as viewing websites with large graphics or listening to streaming audio files, use a lot of bandwidth because youre sending lots and lots of bits.

Bandwidth As Applied To Web Hosting

In your search for a hosting company, you will come upon the term bandwidth many times. In general, most companies are referring to the amount of data that you are allowed to transfer per month.

For example, one hosting company might offer an account that allows 5 Gigabytes (GB), also stated as 5,000 Megabytes (MB), of bandwidth per month for a particular web hosting package. If you go over this allocated amount of bandwidth, you are then charged an extra fee per GB over the limit.

It is very important to note that bandwidth is used every time someone visits your website. Each time an image is viewed, or a file is downloaded, or a page from your website is loaded into a browser, a small amount of hosting bandwidth is used. Basically, every time any information is transferred from one person to another using your hosting account, bandwidth is being utilized.

Estimating How Much Bandwidth You Will Use

Figuring out how much data transfer your site will use involves a simple formula:

(Page Size x Daily Visitors x Page Views x 30 days)

For each of these factors, you should always estimate high just to play it safe.

The size of your web pages will be measured in Kilobytes (KB). If you need a rough estimate, the size of the average HTML page is around 25 KB to 50 KB (graphics included). It is important to not only factor in the size of your HTML page, but also the size of every image used on that page.

The number of page views and daily visitors your site will have depends upon how much traffic your website generates. It is difficult to guess those amounts, but you can gather that information with the use of website statistics programs such as Webalizer. Most hosting control panels let you see statistics on page views and the number of unique daily visitors your site is generating.

Multiple those numbers together and then multiple the result by 30 to see how much bandwidth that would mean per month. For example, if on average 40 visitors come to your site per day, and they surf through 10 pages each on average, and your web pages are 50 KB in size on average, then:

50 KB Average Page x 10 Page Views x 40 Visitors x 30 = 600,000 KB per month
Translated into MB and that would be 600 MB / Month, or just over 1/2 a Gigabyte

As you can see, it would take a good amount of daily traffic before a site is using GB's / month of bandwidth, and statistics show that the average website uses less than 1 GB of traffic per month. If your site also performs functions like straight file downloads, streaming media of any sort, or large amounts of picture files, you'll need to take those file sizes into consideration, as well.

Design Your Website With Bandwidth In Mind

As you build your website, you can do some things to lessen the amount of bandwidth that it will use. It is recommended to optimize the images to reduce their size so that the amount of bandwidth they utilize will be reduced. A second major way is to use Cascading Style Sheets (CSS) or Server Side Includes (SSI) to minimize the amount of HTML code each of your web pages uses. These two technologies are not difficult to learn and both can produce a sizeable reduction in how much bandwidth a website uses.

If you'd like to read some more helpful articles on choosing a low cost hosting provider, then please return to our Hosting Guides section.