After checking several sources, it turns out that some locations have different names for the same size bed or different sizes for the same name. It can get confusing. Unless requested, I make my afghans about 4 inches wider then the mattress/bed size. That seems to be just enough to make sure the afghan stays mostly in place while you are sleeping. If the afghan is going to be used for the couch, I usually go with the twin size. However if the person that is purchasing the afghan is a bigger person, I will increase the width to ensure they are completely covered. Nothing worse then a draft up your back while laying on the couch.
Cot 30″ by 72″
Single 36 in x 75 in
Twin 39 in × 75 in
Double 54 in × 75 in
Queen 60 in × 80 in
Olympic Queen 66 in × 80 in
King 76 in × 80 in
California king 72 in × 84 in
Emperor 84 in × 84 in
Caesar 96 in × 87 in
Oldschool's Notebook 