Extended ATX / SSI-EEB : 12"x13" (305mm x 330mm)
XL-ATX : 13.5" x 10.3" (343mm x 262mm)
Large ATX / SSI-CEB : 12" x 10.6" (305mm x 269mm)
Standard ATX : 12" x 9.6" (305mm x 244mm)
Micro-ATX : 9.6" x 9.6" (244mm x 244mm)
Mini-ITX : 6.7" x 6.7" x 1.7" (170mm x 170mm x 44mm)