How the planner decides
The display limits come from Apple's tech specs and support pages. A MacBook Air with M1 or M2 drives one external display, the M3 Air a second one only with the lid closed, and from M4 on two with the lid open.
Sharpness depends on pixel density. macOS looks best at about 218 pixels per inch, which is 5K at 27 inches. 4K at 27 inches is a good compromise, QHD at 27 inches looks noticeably softer on a Mac.
A dock or hub tidies the cables and charges the Mac over one cable, but it never raises the number of displays your Mac supports.
Questions and answers
How many external monitors can a MacBook Air drive?
M1 and M2: one. M3: one, or two with the lid closed. M4 and M5: two with the lid open.
Can a dock add more monitors to my Mac?
No. Docks and daisy-chaining can run several displays over one port, but only up to your Mac's limit. DisplayLink adapters can go beyond it with a driver, at the cost of some lag.
Is a 4K monitor sharp enough for a Mac?
For most people, yes. At 27 inches it is a little softer than 5K, but much sharper than QHD. If you read and write all day, 5K is the step up.
Which wallpaper size do I need for my new monitor?
The native resolution: 5120 × 2880 for a 27″ 5K display, 3840 × 2160 for 4K. All sizes.
From the blog
Different wallpaper on each monitor on Mac: setup, sizes and dark mode
How to give every display its own wallpaper on a Mac, which size each screen needs (MacBook, Studio Display, 4K, ultrawide), and how to make all of them switch to dark mode together.
New MacBook Pro 2026: wallpaper size, Dynamic Island and what changes
The PROLED MacBook Pro has a taller screen and a Dynamic Island instead of the notch. The exact wallpaper sizes, what is still unconfirmed, and what happens to your old wallpaper.
MacBook and Mac wallpaper size for every model, including the 2026 MacBook Pro
MacBook Air 13″: 2560 × 1664. MacBook Pro 14″: 3024 × 1964. MacBook Pro 16″: 3456 × 2234. The exact wallpaper size and aspect ratio for every Mac, incl. iMac and the 2026 models.