Full-tower and mid-tower cases both fit standard ATX motherboards—by far the most common motherboard size out there. Both can also fit smaller micro-ATX motherboards.

Can Mid tower fit ATX?

ATX motherboards can fit in most full-size and mid-size towers, but it's rare to find a small form factor case that can fit a full size ATX board. There are larger cases designed to support the larger Extended ATX standard motherboards which can usually take ATX boards too.

What is Mid tower ATX?

Generally speaking, mid tower cases are shorter/smaller than full tower cases which means they'll have smaller motherboards, lesser fans, and expansion slots. Most mid-towers measure 18 inches or more in height, while most full tower cases measure 22 inches or more.