Mac computers display application icons at the bottom of your screen known as the Dock. You can rearrange these icons in the Dock, add new ones to Mac dock. You can also adjust icon size on the Dock to make it larger or smaller to suit your preferences.
macOS provides flexibility so that users can tailor their experience to best suit their individual needs and tastes. So if you don’t like the default icon size on the dock, you can change the Dock icon size bigger or smaller according to your personal preferences and workflow.
Method 1. Steps to Edit Mac Dock size (Dock icon size) from System Preferences
Click on the Apple menu icon in the top-left corner of your screen, you will then get the drop-down menu and choose System Preferences from there.
The System Preferences window opens on your screen. Choose Desktop & Dock from the left category of the System Preferences.
Under the Dock section, you will find a slider labeled Size. Drag this slider to the left to make icons smaller or to the right to make icons larger. As you adjust the slider, you will see the Dock icons change in size in real-time.
Once you’re satisfied with the icon size, close the System Preferences window.
Also in the Dock section, you can find the Magnification slider which allows users to control how large the Mac Dock icons get when they roll over them with your mouse cursor.
Method 2. Change icon size directly from the Dock itself
Find an empty space on the Dock (between icons) and right-click (or Control-click) on it. This will bring up a contextual menu. Choose Dock Settings, the System Preferences window opens and you can follow the same steps as described above to change the dock icon sizes.