Dreamweaver calculates size based on the entire contents of the page, including all linked objects, such as images and plug‑ins. Dreamweaver estimates download time based on the connection speed entered in Status Bar preferences. Actual download time varies depending on general Internet conditions.
A good guideline to use when checking download times for a particular web page is the 8‑second rule. That is, most users will not wait longer than 8 seconds for a page to load.