MicroATX

microATX (sometimes referred to as μATX, uATX or mATX) is a standard for motherboards that was introduced in December 1997. The maximum size of a microATX motherboard is 9.6 × 9.6 in (244 × 244 mm). However, there are examples of motherboards using microATX designation despite having a smaller size of 244 × 205 mm (9.6 × 8.1 in). The standard ATX size is 25% longer, at 12 × 9.6 in (305 × 244 mm).

MicroATX

microATX (sometimes referred to as μATX, uATX or mATX) is a standard for motherboards that was introduced in December 1997. The maximum size of a microATX motherboard is 9.6 × 9.6 in (244 × 244 mm). However, there are examples of motherboards using microATX designation despite having a smaller size of 244 × 205 mm (9.6 × 8.1 in). The standard ATX size is 25% longer, at 12 × 9.6 in (305 × 244 mm).