Right-click an empty area on the desktop
Select View
Choose Large icons, Medium icons, or Small icons
Hold Ctrl and scroll the mouse wheel up to increase icon size
Hold Ctrl and scroll the mouse wheel down to decrease icon size
On Windows, open Settings
Go to System
Select Display
Adjust Scale and layout if needed
On Mac, click the desktop
Press Command and J to open View Options
Move the Icon size slider
Close View Options when finished