While Google Analytics is incredibly helpful for monitoring your website popularity and visitor statistics, one thing it can't do is to tell you exactly how much bandwidth your site is using. Depending on your Web hosting plan, bandwidth overage charges may become expensive if your site starts taking more than its share of the monthly allotment. Fortunately, you can use Google Analytics data to estimate your bandwidth usage.
Before You Start
Before using Google Analytics to estimate your bandwidth usage, keep in mind that Google normally doesn't see large non-HTML downloads like PDF or MP3 files. If you're serving a multimedia files, you need another statistics program that measures those downloads. The calculation is most accurate if your site serves consistently formatted HTML pages whose graphics are similar in number and size. Finally, you must have the Google Analytics code installed and working correctly on all of your pages for the entire period you want to measure.
Making the Calculation
To estimate your bandwidth usage, first estimate the average file size of your pages. Find file size information in most HTML editors, or by saving your page, including all graphics, to your hard drive and viewing the file sizes on your disk. Do this with a few different pages to get an average size. Then open Google Analytics and click the "Pageviews" link. To retrieve data for a specific time period, click the date range and select the appropriate start and end dates. Multiply the number of page views by the average file size to determine the approximate bandwidth in kilobytes.
Google Analytics and Bandwidth
Use Google Analytics to make a reasonable estimate of your bandwidth usage, though the definitive source is your Web hosting provider. Most major hosts feature a dashboard with a running total of bandwidth usage. Use this total to determine whether you're within your monthly limits. If you believe there's a problem with your host's bandwidth figures, contact the support desk. Alternately, install a web statistics package that uses server data to track bandwidth usage.