How many shutter panels do I need for each window? Usually, the larger the window, the more shutter panels you’ll want on it. The optimal design is to use a single panel for windows up to 26 in. wide, two panels for windows up to 50 in. wide, and four for windows up to 98 in. wide.Single wide panels are not as room-friendly as multiple panels. Often, wider panels can’t fit flush against the wall due to their size. Two smaller panels don’t have that problem.For windows that you might want to open or shut regularly, you’ll be better off with multiple panels, since they’re easier to open and get more support from the shutter frame when you do operate them.