there is plenty of space and bandwidth talks happening nowadays with the hosts trying to outdo each other, the client running after the space and bandwidth, seems more of a manner that no matter what one really know what he/she needs in this area, may be this needs to be discussed :-
how much space you need:
think of your account as a sub directory (or folder) web hosting on your hard disk. To determine the amount of disk space you will need, in Microsoft windows explorer or my computer simply open and click on the folder that contains your website files. Create a new folder for your website if you have one and then move all files that you plan to host on the web server in this case. What you have to do is now right click on your folder to check the size of the file and now you know how much disk space you will be using on the server. This site is around two megs.
how monthly transfer (bandwidth) data do you need:
try to use the following formula to estimate the monthly transfer of data from your site.
* = total monthly usage allowance of data transfer.
for example: If we had a site with 30 pages 8 KB each, on average 50 KB worth of images of each page and 50 visitors per day who saw an average of 4 pages, you would have the following formula: * = KB 348,000 so we would use 348,000 KB, or about 340 MB bandwidth per month. EH well, within the limits of our hosting plans.
it is difficult to generalize how a site’s data transfer will use without looking in particular, but in most cases, it is very rare for a personal site or a small business to use more than one gigabyte (GB) or transfer of data per month. Starting with a limit of one gigabyte per month data transfer is probably appropriate for most new sites. If your average web page is 20 KB in size. 1 gig or transfer helps more than 50,000 visits per month at this size! If your average page size is closer more visits per month.