I have a small 5 cup maker, I use two heaping coffee scoops(1/8th cup) which gets me two 16 ounce cups of coffee. So...yes, size (of cup) does matter. If I wanted just one cup I would use one heaping coffee scoop and fill water to the 2.5 cup line.
“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.” - Albert Einstein