Different size of the same graphic

[Jorgen]

I am using Visio 2003 Standard to create some flowcharts for my intranet web
site.
The intranet site is created in Frontpage 2002 Standard.
When I save the graphic as file.gif it has the size 705 x 343 on the HTML
page and the file size 20 kb.
When I save the graphic as file.wmf it has the size 832 x 411 on the HTML
page and the file size 8 kb.

I have the experience that the wmf-format shows better on the screen. Very
clear and distinct text and lines. That is why I like to use this format.

But the graphic is larger than expected when I use the wmf-format compared
to the gif-format.
Why is this difference??
Jorgen