How many shutter panels do I need for each window? For the most part, 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 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 room-friendly as two separate panels. Often, wider panels won’t fit flush against the wall due to their size. Multiple small panels resolve that.For those windows that you’ll want to open or shut regularly, you’ll be better suited with multi-panel shutters, since they’re easier to open and have more support from the frame when you do open and shut them.