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 multiple panels. Often, wider panels won’t fit flush against the wall due to their width. Multiple small panels resolve that.For those windows that you might want to open or shut often, you’re usually better off with multi-panel shutters, since it’s easier to open them and they get better support from the shutter frame when you do operate them.