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 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 two separate panels. Often, wider panels can’t fit flush against the wall due to their width. Multiple small panels fix that.For windows that you’ll open or shut often, you’ll be better off with multiple panels, since they’re easier to open and have more support from the shutter frame when you do operate them.