I believe most manufacturers go by 5 or 6 ounce cups.We had a 12 'cupper' when we both drank caffeinated coffee. But when that one died it was replace with a 10 'cupper'.
My little cuisinart is 4 cups. But they must be tiny cups. I make 1 12 oz mug with it in the morning and the pot is 3/4 full.
Sorry America, But A Cup Isn't 8 Ounces Everywhere Else In The World