Click on an empty area of your desktop to make Finder active. Then, hold down the Control (Ctrl) key and scroll up or down with your mouse wheel or two fingers on a trackpad. Alternatively, on a Mac trackpad, you can use a pinch gesture (pinch in to make icons smaller, spread two fingers apart to make them larger). This method offers a smooth, continuous range of sizes.
Right-click (or Ctrl-click) an empty area of the desktop, then select “Show View Options” (or just “View Options” ). A window will appear. At the top, you’ll see a slider labeled “Icon size.” Drag the slider left to decrease or right to increase the icon size. This same panel also lets you adjust grid spacing and text size. how to adjust desktop icon size
Here are the different methods to resize icons on Windows and macOS. Click on an empty area of your desktop to make Finder active