You just received a higher than normal monthly bill on your credit card for web hosting. Your hosting company explains that you exceeded your monthly minimum for "bandwidth usage" and suggests reducing the size of your web site files.

What is bandwidth usage?
What does bandwidth mean?
How much bandwidth do you need?
How can you reduce bandwidth usage?

Let's discuss each of these topics in more depth.

What is "bandwidth usage?"

This refers to the total amount of information that has been served to your web site visitors each month. Every file on your Web Site has a specific size (e.g. 22K). Every time a visitor downloads that file, your bandwidth usage goes up by that amount.

The larger the file, the higher the bandwidth usage when it is downloaded. The more traffic to your site, the more bandwidth you will use.

What does "bandwidth" mean?
Bandwidth refers to the amount of data that can be transmitted in a fixed amount of time. The "data transfer rate" is the speed with which data can be transmitted from one device to another. Data rates are often measured in megabits (million bits) or megabytes (million bytes) per second. These are usually abbreviated as Mbps and Mbps, respectively.

Bits and Bytes
8 bits = 1 byte.
1,024 bytes = 1 kilobyte (Kb).
1,024 kilobytes (Kb) = 1 megabyte (mb or meg)
1,024 megabytes = 1 gigabyte (gb or gig)

How much bandwidth do I need?
To determine how much bandwidth you need, estimate the file size of each web page, and then multiply it by the number of pages on your web site.
Multiply this figure by the number of the number of page views you expect per month from your site.

For example, if your web page consists of two 15Kb images and 3Kb of html, you would have 33Kb of data for that page. Now multiply this by the number of page views you expect to have per month (e.g. 100,000 per month). This would mean 3.3Gb of data needs to be transferred per month for that page.

Now recalculate this number for each page, and you'll know approximately how much bandwidth your entire site requires.

How can you reduce bandwidth usage?
The easy way is to reduce the size of the files on your site, particularly images and other graphics. For example, you have a large image (i.e. 200KB) on your web page that is downloaded by each visitor every time the page is requested. If you reduce this image to 20KB or remove it altogether, it will dramatically cut your bandwidth usage. It will also speed up your site's performance.

For more information on optimizing images for the Web, read my article, "Preparing Images for Your Web Site", (www.isitebuild.com/imageoptimization2).

Web Sites that have MP3s to download, movies, music playing in the background and large images, will obviously have a higher bandwidth. Large web sites or sites that expect a lot of traffic, will also use a lot.

If your site has mainly html pages and small images, your bandwidth will not be that high.

Bandwidth Tools

Monitoring bandwidth
http://www.utoronto.ca/ucres/netup.htm

Web Page Checker
http://www.searchengineworld.com/cgi-bin/page_size.cgi

Tuning up your Web Site
http://websitegarage.netscape.com/

Bandwidth Tips
If you make changes to your site by adding more files and/or web pages, recalculate your web site file size.
Estimate how many visitors will be accessing your web pages over the next few months.
Recalculate the bandwidth usage for your site. You may need more web space and bandwidth for your site to function effectively.
Check with your web hosting company to upgrade your hosting plan.

Conclusion
Now you can avoid the shock of exceeding your monthly bandwidth usage and paying higher hosting fees. You are now ready to receive more traffic to your site and therefore make more sales.