I am measureing just under 244mm across the back of the board (where the connectors are) and 245mm on the other side (parallel to the PCI slots)
~9.5 inches x 9.5 inches
I couldn't even find the dimensions in the manual. Abit still blows the sh!t out of Biostar as far as information though
all in all, I think this is a killer board for the price. Very stable, easily overclocked my duron 33% (100FSB to 133 FSB).
If you get this board and don't have a case, consider the
Enlight 76020b1, it's got 90mm fans and a 300W PS. I ordered mine from directron, upgraded to a dual fan 320W TTGI PS, and it was only~ $70 shipped. I cannot believe how much quieter a 90mm fan is than an 80mm fan, cfm for cfm. food for thought