How to make Finder windows open bigger on a Mac

Can I set a default Finder window size?

No. Finder has no setting for the size of new windows, in Finder Settings or in System Settings. What you can control is how quickly a window gets to the size you want, and whether you need a new window at all.

How do I make a Finder window fill the screen?

• Press fn ⌃ F on macOS 15 and later. The window fills the screen, with the menu bar and Dock still showing.
• Hold ⌥ and click the green button.
• Double click the title bar, if Window title bar double-click action is set to Fill or Zoom in Desktop & Dock settings.
• Choose Window, Fill from the menu bar.

How do I stop opening new small windows?

Use tabs. Turn on Open folders in tabs instead of new windows in Finder Settings, General. Size one Finder window the way you like and every folder you open lands in it as a tab, at that size. See opening folders in tabs.

Can a script open Finder at an exact size?

Yes. This opens a Finder window and sets its position and size in points, left, top, right and bottom:

osascript -e 'tell application "Finder" to set bounds of (make new Finder window) to {80, 60, 1280, 860}'

Save it as a Shortcut with a keyboard shortcut, and you have a key that opens Finder at your size. More in setting an exact window size.

ClutterFreeMac takes this further for every app: a per app rule can open an app's windows at full width every time, and new windows open beside the one you are using instead of in the middle. Try it in the demo.