What size motor do l get with my window size

it depends on the size of your window or opening we match the window size with a motor that is 20% over capacity
link below for agents
http://www.asa-mingardi.org/system/be/documentViewer.stub.php?xfile=a221c175e4a0046a2bcf17317f65fb61a4c1c85be055cbdbf79f3dffc6cb1a8be7c685b4a36a6604b36d56ad1c17d33c869777ee4216657a9cb16d787569e4018ba6dc8ce877fed5145baf541ee27486b9e0f4c5f62d146e5ee07d00899a73801a6365b7