Choose which count you want from the drop-down menu. Fat quarters are approximately 18" by 25" for 16 and 18 count, 18" by 20" (approximately) for 20 count. Purchase TWO to get a fat half (36" by 25" for 16 and 18 count; 36 by 20 for 20 count.) Purchasing a quantity of FOUR will get you a full yard. 
 
Note: If you purchase THREE, you will get a fat half AND a fat quarter. I don't do fat 3/4's.