How many shutter panels do I need for each window? Usually, the the large the surface area of your window, the more shutter panels you’ll need. The optimal design is to use one 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 aren’t as user-friendly as two separate panels. Oftentime, wider panels can’t fit flush against the wall due to their size. Multiple small panels solve that problem.For windows that you might open or shut regularly, you’ll be better suited with multiple panels, since they’re easier to open and have additional support from the frame when you do open and shut them.