The difference between 7″ and 7.85″ is everything

Here’s why I think there will be a tablet from Apple that’s optimized for reading and has a 7″ retina display that runs iPhone apps unmodified, not a tablet with a 7.85″ display that runs iPad apps unmodified.

Perhaps you’ve read these Steve Jobs quotes before, they go something like this:

The 7-inch form factor is not a good size for tablet applications” and “7-inch tablets should come with sandpaper, so that users can file down their fingers so they can use them.

Note the words in bold.

Every rumor and theory about a smaller iPad I have seen seems to claim it will be 7.85″ with a 1024×768 screen. If that were the case, Steve Jobs would be right on the money with the above quotes. A 7.85″ 1024×768 display would be appropriate if the smaller tablet were designed to run iPad applications, because these applications could run unscaled on the device, at a 1:1 pixel ratio. However, the PPI of that 7.85″ screen would be 163. But the size of the user interface elements on iPad applications are tailored for a 132 PPI screen. If squeezed into 163 PPI, every button and control would become smaller, harder to accurately touch. Hence the need for sandpaper.

The same argument applies if the 7.85″ tablet had a retina display with the same resolution as the new iPad’s 2048×1536. It would have 326 PPI, but the UI elements of retina iPad applications are designed for 264 PPI. Sandpaper required.

But consider if the new tablet had a 7″ screen. What’s so special about 7″? A couple of very interesting things.

A 7″ diagonal screen (7.08″ to be exact) just happens to be the exact size of two by two iPod touch retina displays. That’s a 4″ x 6″ display surface. An iPod touch screen has 326 PPI. The 7″ screen would also have 326 PPI just like iPhones and iPods. This would yield a resolution of 1920 x 1280. This resolution would be able to run current retina iPhone applications pixel perfect using the traditional 4:1 pixel scaling, like retina displays do with non-retina apps.

What’s so special about that? By running iPhone applications on a larger screen, as opposed to running iPad applications on a smaller screen, you don’t need the sandpaper anymore. Heck, if you have fat fingers, you’ll rejoice. Larger touch targets are just easier to hit, but still look amazing, especially text, which will be drawn using the full 1920 x 1280 resolution. Anyone that finds the iPod touch or iPhone screen slightly cramped would love it, and could continue to enjoy amazing apps like iMovie, iPhoto, and other apps designed for iPhone.

So a 7″ tablet wouldn’t be an “iPad mini”, it would actually be more like an “iPod maxi”. But that’s getting ahead of ourselves. A 7″ or 7.85″ tablet still has to have a clear purpose. To be able to do something far better than the smaller devices (iPod touch and iPhone) and far better than larger devices (the iPads).

The answer is: reading, and long “consumption” sessions. Reading is something that is not comfortably done on an iPad, compared to a dedicated e-reader like a Kindle. That’s because it is relatively very heavy (over 600 grams), and too large. The new iPad is even heavier. You can’t hold these up comfortably. They are also rather expensive, starting at $400, compared to a dedicated e-reader. That’s why my friends with iPads that like reading also bought and use a Kindle. Reading is also cumbersome on an iPod and iPhone, because they are just too cramped and tiny. For comfortable reading, you need a device that’s not more than 400 grams (determined by reading reviews of various e-readers), with a long lasting battery, a screen more tailored to reading than other iOS devices, and it has to be more affordable than an iPad.

The Apple “e-reader” I’m about to describe wouldn’t just be a great, inexpensive and sufficiently light reading device with a color retina display, it would also be a full iOS device capable of beautifully running iPhone apps.

An iPod touch costs $200. It is 0.28″ thick (7.2mm). It weighs 105 grams. If you think of a 7″ iOS “reader” device that is essentially 4 iPod touches put together in 2 x 2 formation, this device would end up being about 0.29″ thick (7.5mm), weigh 350g, and beautifully run retina iPhone apps unmodified using a perfect 4:1 pixel ratio. It would be slightly thicker for structural strength and extra battery space. It wouldn’t cost $800 because you don’t need 4 times the electronics.  It would have more battery life than an iPod touch thanks to far more battery space. It would also weigh less than 4 iPod touches because not everything is multiplied by 4. Cost? I’d say $250 because the larger 1920×1280 display would cost slightly more, even if it would be iPod touch quality (inferior to iPhone or iPad display quality) and Apple factories are already perfectly tooled to make 326 PPI iPod-quality displays.

Apple would also optimize the display for “reading”, meaning, applying anti-reflection, more precise dimming and other technologies to it that it normally wouldn’t need or desire for iPods, iPhones or iPads. Yet iPhone apps would still run nicely on it, making it far more multi-purpose than a mere Kindle with e-ink, even if still not as awesome for reading in bright daylight.

E-readers are a nice market segment exploited by Amazon, wide open for Apple to expand into and dominate with iOS.


  1. Leukotriene says:

    “However, the PPI of that 7.85″ screen would be 163. But the size of the user interface elements on iPad applications are tailored for a 132 PPI screen. If squeezed into 163 PPI, every button and control would become smaller, harder to accurately touch. Hence the need for sandpaper.”

    That’s a good argument in theory, but it just doesn’t hold water when you actually visually compare the iPad interface at 163ppi to, for example, the now-shipping iPhone interface. Tap targets are (conspicuously) precisely the same between a hypothetical 7.85″ iPad and a currently shipping iPhone.

    The proof is better explained with a photo:

    The iPad in this photo is actually a picture of a 7.85″ iPad drawn to scale (there is a ruler next to it to clarify that). As you can see, the tap targets are precisely the same when you hit the magic iPad size of 7.85″.

    So, following the logic of your argument, if the tap target size of a 7.85″ iPad (displaying iPad UI elements) is too small and requires sandpapering the fingers, then the same must also be true of currently shipping iPhones and iPod Touches. The best counterargument against the argument you laid out in the above blog post is Apple’s own devices.

    • Odi Kosmatos says:

      The targets you refer to are the same because the software running on the iPhone is an iPhone app, sized for the iPhone, and the software running on the iPad is an iPad app, sized for the iPad. But an iPad mini, with the same amount of pixels (1024×768 or 2048×1536), but smaller pixels, will necessarily have smaller text and smaller touch targets if it is running software designed for the larger iPad at a 1:1 pixel ratio.

      • Leukotriene says:

        Yes, they’ll have smaller pixels than the current iPad, yet precisely the same sized pixels AND same sized UI tap targets as an iPhone. Apple in their HIG says that 44×44 points is the minimal size for a usable tap target, and a 7.85″ iPad running a 1024×768 app just perfectly satisfies that requirement, as does a current 3.5″ iPhone running a 960 x 640 app.

        I’m agreeing that the tap targets will shrink when compared to a 9.7″ iPad. My point is that they will shrink down to *precisely* the same sized tap targets as a current-day iPhone. And that only happens at the magic size of 7.85 inches. Any smaller, and the tap target falls below 44×44 points; any larger and the ppi increases such that it can’t be cut out of the same display material that the iPhone/iPod Touch is already made out of. The magic number is 7.85 inches, not tenth of an inch higher, not a tenth of an inch lower.

        This 7.85″ number could have been mathematically calculated years ago when the original iPad’s resolution was first announced. This number is a property of both the resolution of an iPad app and the pixel density of the display sheets that iPhone screens are cut out of.

        Yet somehow, incidentally, this magic number has shown up independently as part of several rumors, coming from both Asian suppliers (sketchy) and John Gruber (reliable). Where there’s smoke, there’s fire. To abuse this metaphor further, the smoke is both mathematical truth AND it’s repeated rumor coming from multiple, socially separated sources.

        I’m going with Occam’s razor here: what is the likelihood that this magic number of 7.85″ is just accidental?

      • Leukotriene says:

        By the way, just to clarify further…

        The buttons and UI elements on an iPhone today are smaller than the buttons and UI elements on an iPad today. Just whip out an iPhone and iPad, and open Safari. Note that the address bar is taller on the iPad’s version of Safari by a good amount. Same thing with other analogous buttons.

        Now take that same iPad, and shrink everything down to 7.85″. Not 7″! Not even 7.9″! I’m talking EXACTLY 7.85″.

        Compare the UI elements between your newly shrunken iPad and youriPhone. Lo and behold–the Safari address bar is the same height. The buttons are the same width and height.

        Now convince me that’s not a coincidence!

      • Odi Kosmatos says:

        You and MG Siegler (posted “Seven” on techcrunch yesterday) have turned me into a believer in 7.85″ instead of 7″ after all. Good points you make. iPad is more important than iPod, too.

  2. Geoff Harrop says:

    I agree with your thinking totally, an iPod maxi would be great for consuming tv to movies too and would fit well with the new iTunes match developments. The kindle fire is no threat to the iPad but I believe many owners dof it do find it very useful for the sort of media consumption you refer too. Add to that mobile gaming as an alternative to. Nintendo or play station and you could have a very high volume market…..

  3. I like your logic, I just wanted to bring a couple issues to light…

  4. Great article.

  5. This is the best theorization on a new iPod Max or iPad Junior. I think Kosmatos is correct, and I hope he is too. Apple shouldn’t make this thing to compete with Amazon (respond to the market) but rather to perform a task not already being performed by other hardware (i.e. reading). With iCloud, no need to worry about syncing, one could have a device like this sitting around ready for use, even with iPad and iPhone around. However, questions of usefulness remain.

  6. Don’t forget kids, though. 3-8 year olds typically lay down the iPad on the floor, a table or their lap, and clumsily proceed to use it with two fingers thereafter.

    A 7-8″ device, whichever resolution it is, would suite them well. They’d be able to manipulate it as appropriate — and they don’t exactly have fat fingers… Keep primary school textbooks in mind, too. And games, obviously.

  7. You may be right about the machine but I can’t see that price working in 2012. A new machine will have at least an A5 (touch is on A4) making it (with the retina display) a comparable if not better device than the iPad 2 at $400.

  8. Andy Hullinger says:

    I like the thinking, but the flaw in the argument for a reader is the dearth of long form content apps for the iPhone. None of the Magazines or even iBooks Author textbooks are being created to work on the iPhone, and simply scaling up (even in a quasi responsive layout way) existing iPhone text content will seem unsatisfying compared to a 10″ display. You’re describing a use case that really does not exist, and all the momentum is moving publishing toward richer, and finally coherent, multimedia for tablets. I think a maxi iPod is increasingly irrelevant as the iPad becomes better at content creation as well as consumption.

  9. An iPod Touch has a diagonal of 3.54″ and a ratio of 3:2, meaning in portrait mode its 2.95″ high x 1.96″ wide. Lay four of these out and you’ve got something 5.9″ high x 3.92 wide. Which would make the display about 7.1″ diagonal.

    Take a snapshot of something on your iPhone screen and let iCloud replicate it to the photo stream on your computer. Open the image and stretch it to this size. Use a ruler to get it about right. Look at it. Does this look like a good idea?

    The icons on the home page are about the size of a US nickle. The spacing between the icons is about equal to the size of a US quarter. Everything looks a bit cartoonish, like its one of those phones with huge buttons for people who can’t see very well any more. Sure the text will be sharp, but you’ll still only see 4 email messages in your Inbox on screen at a time (with a summary and three lines of text from each, just like on your iPhone). An email will still only show the first 11 lines of text with under 50 characters per line. All the fonts will be H-U-G-E.

    Try it yourself. See if you think this is believable. I don’t.

    And that’s ignoring the issues zwei brings up, that Apple wouldn’t do this without allowing developers to make use of the higher resolution, which would again introduce another resolution into the app eco-system, requiring yet again more graphics options, and bloating up the already large apps once again. I think if this were the option Apple were considering they really would say lets just forget this one for a while.

  10. All these ~7″ iPad discussions seem to me to be really fantasies about a cheap iPad that try to justify it with a size argument that reckons if it were smaller it must cost less.

    The statement that “an iPod touch costs $200” should be “an 8 GB iPod touch costs $200”. At least this article acknowledged the iPod touch – most forget that a 32 GB iPod touch costs $299 and there is not a 16 GB touch that costs $100 less – it’s an 8GB model, and a 16GB iPad 2 (non-retina display) is $399.

    The 32GB wifi retina iPad is $599 and a 32GB wifi retina iPod touch is $299. I’m going to scale cost in between linearly with display area, which isn’t perfect, but it roughly captures display size and battery size. I get $434 for a 7″ 4:3 display, so call it $399-$449. If we use iPad flash price deltas, then you could say a 16GB model could be $299-$349.

    A flaw in my reckoning is that new iPad has an A5X and 1GB RAM and the touch has an A4 with 256MB RAM. A hypothetical iPad mini might use just an A5 and 512MB RAM, so we’ll go with the higher end of the range and say $349.


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