The Apple Watch screens have a resolution of 390x312 and 340x272

Apple made a point when introducing the Apple Watch to show that unlike the various other smartwatches out there, theirs was coming in two different sizes, and now we know that also means two different resolutions. The reasoning is almost entirely gender fashion based: bigger watches look goofy on smaller female wrists, so they get smaller watches. That means the Apple Watch has two different-sized displays — the larger 42mm-tall watch has a 390x312 screen (38mm diagonally), while the smaller 38mm-tall Apple Watch has a 340x272 screen (33.3mm diagonally). This does compare well to competing Android Wear smartwatches, which tend to feature screens that aren't quite as pixel-dense.

This means that developers building Apple Watch apps will have to design for both screen sizes. Most of the work will be the same, generally, as women tend to also have smaller fingers than men and can work the smaller targets (it's not a huge size difference, after all), but any graphical assets will have to be produced in both sizes. For example, a notification icon on the 42mm Apple Watch would be 32px tall, while on the smaller model it will be 29px. With such a small difference in size there's no way to elegantly scale down the icon without losing quality.

Sure, there are ways Apple could have gotten around this, but there's a reason they went the route they've gone. Mandating much higher resolution images so they could be easily scaled down to size while maintaining quality would lead to bloated apps. Scaling the 42mm Apple Watch's display down to to the 38mm size with the same resolution would add cost to the manufacturing process as well as through a wrench into building apps that depend on UI items of a specific size regardless of the size of the watch. So this is the solution we've got, two different resolutions with separate design requirements. It's all part of the WatchKit SDK that was released today.

Source: Apple Watch Human Interface Guidelines (opens in new tab)

Derek Kessler is Special Projects Manager for Mobile Nations. He's been writing about tech since 2009, has far more phones than is considered humane, still carries a torch for Palm, and got a Tesla because it was the biggest gadget he could find. You can follow him on Twitter at @derekakessler.

10 Comments
  • At around 330 ppi it's going to be very nice screens
  • I really wish they had a "dumbed down" version of the iWatch. I keep telling myself I won't buy a gen1 iWatch but I doubt I'll resist. I'm sure it will look great but if it's tethered to my iPhone 6+ then, other than notifications and quick responses, I just don't know many reasons for why I'd prefer to look at the watch screen rather than the phone.
  • I have to take issue with this line: "The reasoning is almost entirely gender fashion based: bigger watches look goofy on smaller female wrists, so they get smaller watches." I'm a guy with a small wrist, and I prefer a smaller watch face. And I have women friends who like to wear big watch faces. I think the two different sizes are not at all gender-based, but they're rather Apple's way of giving all consumers a choice, whether male or female, big-wristed or small.
  • I stopped reading this at: "The reasoning is almost entirely gender fashion based: bigger watches look goofy on smaller female wrists, so they get smaller watches. "
    An extremely narrow POV. So, by your logic, the only people that should get the big Apple Watch are men? However unintended that statement may be, i suggest a revision...and i'm kind of shocked the editor's editor didn't catch. However, i'm sure this is considered and op-ed, so you have the right to your opinion. I'm just saying: *disagree*.
  • Oh boy. Fragmentation!
  • Nah just designing for responsive.
  • Don't see the fragmentation Posted via the iMore App for Android
  • When there was one iPhone screen size, everyone was screaming "Android fragmentation!", even though Android had the building blocks to handle different DPI buckets and screen sizes from day one. Now that Apple has many screen sizes, they had to implement a way to handle multiple screen sizes in an already mature OS. Notice the fragmentation crowd seems to have finally shut their traps?
  • Meaning the iPhone 6 and 6+ is fragmentation. And the 5 and 4s is fragmentation. Because different screen size means fragmentation. Posted from the amazing whatever device I can afford because I'm a broke college kid.
  • very low!