How to Set Up External and Dual Monitors on a Mac
Introduction
When you work with a lot of documents at once, or find yourself with a lot of windows open, it can become welcome, if not necessary, to have more display room for your work all at once on your computer. Rather than buy a single, larger monitor, you can use a second one to display either the same or different windows.
This guide will take you through the basics of setting up a second monitor for your computer.
1 Set Up the Work Space for Dual Monitors
On Your Desk

- Make sure there's enough space for both monitors to fit on the desk where you don't knock against them.
- Make sure you can still reach your keyboard and mouse comfortably.
- Make sure you can see both monitors when you sit down and make sure viewing the two monitors does not hurt your neck.
For Each Monitor on Your Desk
- Each monitor needs a power cable or adapter, and an outlet to plug it in. The outlet could be on a power strip or power protector.
- A video cable such to connect to your Mac that fits one of the ports on your monitor. This will either be a thunderbolt cable or a mini-display port. You may need an adapter for this.
Desktop
Laptop
For Your Mac to Connect to a Monitor
- You need a port for each monitor. Macs have Thunderbolt connectors and mini-display ports. You may need an adapter for this.
- The ports on your computer must match the cables coming from both your monitors. Do not force the cable connectors as they should slide in easily.
2 Connect the Additional Monitor
- Connect the video cable to your monitor.
- Connect the other end of the video cable to your computer.
- Connect power to your new monitor:
- One connector (1) plugs into the monitor.
- The other connector (2) plugs into a power socket.
- And sometimes, a third (3) connector plugs into the supply itself.
- Turn on your monitor.
- Turn on your computer.
3 Manage Settings for Mac Monitors
Now that you've got everything set up, turned on, and working properly, you can adjust the settings to make it perfect for you. If you want to just mirror a smaller monitor on a larger one, you can do that. If you want to extend the display to add more space, you can do that too!
Let's open the display settings and take a look around.
Access Display Settings
- Click on the Apple menu and click System Preferences.
- Click on Displays.
Extended Display
You can maximize your workspace with extended desktop mode, which lets you enjoy full-screen apps and windows on each monitor.
- Click on the Arrangement tab.
- Make sure that Mirror Displays is unchecked.
- You can position your monitors by dragging the monitor to rearrange how they show up.
Mirrored Display
With video mirroring, all of your displays will show the same apps and windows.
- Click the Arrangement tab.
- Make sure Mirror Displays is checked.
Was this content helpful?
YesNoWhen you work with a lot of documents at once, or find yourself with a lot of windows open, it can become welcome, if not necessary, to have more display room for your work all at once on your computer. Rather than buy a single, larger monitor, you can use a second one to display either the same or different windows.
This guide will take you through the basics of setting up a second monitor for your computer.
On Your Desk

- Make sure there's enough space for both monitors to fit on the desk where you don't knock against them.
- Make sure you can still reach your keyboard and mouse comfortably.
- Make sure you can see both monitors when you sit down and make sure viewing the two monitors does not hurt your neck.
For Each Monitor on Your Desk
- Each monitor needs a power cable or adapter, and an outlet to plug it in. The outlet could be on a power strip or power protector.
- A video cable such to connect to your Mac that fits one of the ports on your monitor. This will either be a thunderbolt cable or a mini-display port. You may need an adapter for this.
Desktop
Laptop
For Your Mac to Connect to a Monitor
- You need a port for each monitor. Macs have Thunderbolt connectors and mini-display ports. You may need an adapter for this.
- The ports on your computer must match the cables coming from both your monitors. Do not force the cable connectors as they should slide in easily.
- Connect the video cable to your monitor.
- Connect the other end of the video cable to your computer.
- Connect power to your new monitor:
- One connector (1) plugs into the monitor.
- The other connector (2) plugs into a power socket.
- And sometimes, a third (3) connector plugs into the supply itself.
- Turn on your monitor.
- Turn on your computer.
Now that you've got everything set up, turned on, and working properly, you can adjust the settings to make it perfect for you. If you want to just mirror a smaller monitor on a larger one, you can do that. If you want to extend the display to add more space, you can do that too!
Let's open the display settings and take a look around.
Access Display Settings
- Click on the Apple menu and click System Preferences.
- Click on Displays.
Extended Display
You can maximize your workspace with extended desktop mode, which lets you enjoy full-screen apps and windows on each monitor.
- Click on the Arrangement tab.
- Make sure that Mirror Displays is unchecked.
- You can position your monitors by dragging the monitor to rearrange how they show up.
Mirrored Display
With video mirroring, all of your displays will show the same apps and windows.
- Click the Arrangement tab.
- Make sure Mirror Displays is checked.