How many shutter panels do I need for each window? Typically, the larger the window, the more shutter panels you’ll need. The optimal design is to use a single panel for windows up to 26 inches wide, two panels for windows up to 50 inches wide, and four for windows up to 98 inches wide.Single wide panels aren’t as room-friendly as two separate panels. Oftentime, wide panel shutters can’t fit flush against the wall due to their size. Two smaller panels solve that issue.For those windows that you’ll open or shut often, you’re usually better off with multiple panels, since they’re easier to open and get more support from the frame when you do open and close them.