On the Internet website users or visitors are an impatient lot and do not wait long for a web page to download on their web browser they move to next website if the downloading speed is slow. Hence website designing to be successful on the Internet it should down load fast. Fast downloading speed is a factor taken into consideration while ranking your web site by the search engines.
Before calculating the downloading speed of the web pages during web development the following factors have to be taken into account. The individual connections to the Web are not uniform as some may be using old modems with slower speed or some may be using broadband connections which are faster. The disk, ram and CPU speed of the users systems are factors too, the server speed, over loading and the route traveled to your ISP and its performance are also critical.
Hence when you consider the weight of your page then you should know that your page should load reasonably faster in the case of all users of the Internet. Check the download speed of the index page with no files in the cache. This will help you assess the down loading speed of other pages if the graphics and navigation buttons used are similar.
A good web designer will use high resolution but light image graphics in proper format as photographs in jpg and banners etc in gif mode. The image weight should be maximum up to 30 kilo bytes while an image weight of around 15 kilo bytes is ideal. Formatting also matters in this case and use of external css and server side scripts is much better.
Keep a tab on you host or the hosting server as the service providers often makes extra bucks by selling more capacity than they have.