Determining the Numbers
When launching a new website, calculating the bandwidth is sort of a hit or miss. The best course of action is to track the site’s activity monthly for the first couple of months after it goes live so that the actual monthly usage can be seen. For a website that is a bit more established, it is easy to calculate the estimated bandwidth. To do this:
In kilobytes, estimate the average page size of the site. If this is unknown, a load time test on a few pages can give the information to find the average. This value should then be multiplied by the monthly average number of visitors. The result of that should be multiplied by the average number of page views per visitor.
Do remember that these calculations should be inclusive of every site that is hosted on the server. For example, if 10 domains are run on the same account, add up the size of the pages, the visitors, and the page views. These calculations give a pretty accurate idea of the amount of bandwidth a website needs, but it does require just a bit of math. These numbers don’t give the whole picture so it is important to factor in other challenges that are present.
Factors to Consider
Many websites do not use much bandwidth if they are not hosting large media files or streaming, and can get away with under 10GB a month. As an example, a decently popular blog with about 1,000 daily visitors, an average page size of 100 KB, and an average of 2 page views per visitor will only need around 8.5 GB per month of bandwidth. This is just an estimate, and the numbers stand true at this point in time. This is the reason to take into account having room to grow to avoid changing hosts or plans every time that the website data shifts. Bandwidth consuming levels can change with many things like changes in a layout, growth of traffic, growth room, and spikes in traffic. When changing the layout of a site, it is possible to unknowingly increase the size of the page, which will use more bandwidth to load. Just one social news site mention may cause a traffic spike, possibly catching you off guard and causing the bandwidth to double or triple. Many website owners look at bandwidth the same way that they look at firewood, when the general rule is to gather as much as you need, and then triple it. Bandwidth needs will want to be multiplied up to tenfold. It is possible that the website will never use more than just a fraction of the bandwidth paid for, but it does spare the user from the overage charges of unexpected heavy traffic. Extra bandwidth is affordable when contained in a service plan, and it ensures a peace of mind to know that the website will be prepared for any future expansion or heavy traffic.