800×600 has been the standard browser screen size for years; however, only 8% of the population still use this resolution. 1024×768 and larger now represent over 90% of the Internet. With this in mind, it’s time to start developing websites with 1024×768 in mind. However, that doesn’t mean that a person actually has this much room to view their pages, and many people with better resolutions don’t have their browser maximized.
With a couple of standard browser plugins installed, here is what I found for the two current browsers, IE7 & FF2.
1024×768
Internet Explorer Version 7 - 1003×517 usable space.
Firefox Version 2.0.0.6 - 999×546 usable space.
1280×1024
Internet Explorer 7 - 1259×773
Firefox 2.0.0.6 - 1263×810
Therefore, above the fold browser space for the majority of today’s browsers is 999×517.