You can figure out estimated bandwidth usage of your domain using below terms:
Average Bandwidth usage = (your average page size (including graphics)) * (the number of page views)
Example:
With an average page size of 50 KB, and around 60000 page views per month, you will require an average of 3 GB bandwidth per month (60000 * 50 = 3000000 KB). Following is the calculation:Average Bandwidth usage = (your average page size (including graphics)) * (the number of page views)
Average Bandwidth usage = (50 KB) * (60000)
Average Bandwidth usage = 3000000 KB ~ 3 GB
In this case, you should get a plan with 4 to 5 GB of bandwidth limit per month.