There's a handy little shortcut we all take when we talk about how big a phone is. Instead of talking about actual dimensions, we use the size of the display. It's useful short-hand, but now that phones are getting bigger and every tenth of an inch matters, it's time for a reminder: screen size and phone size aren't the same thing. In fact, they can be wildly different.
Above you'll see the Nexus 6 (5.96-inch screen), the Galaxy Note 4 (5.7 inch screen) and the iPhone 6 Plus (5.5-inch screen), and although their screen sizes vary by up to half an inch—that's a lot for a phone!—they're all roughly the same size.
On the one hand, that screen size does not equal phone size is obvious. Of course it doesn't! There's a bunch of stuff around the screen. Duh. But it can still get confusing or misleading, especially when a phone with a big screen and a big body around it becomes the go-to reference point. Mainly, I am talking about iPhone because iPhones are big.
Take the iPhone 6, which has a 4.7-inch screen and feels a whole lot bigger than the iPhone 5S did. Here's the thing though; the iPhone 6 is also big for a phone with a 4.7 inch screen. Take a look. Here's the Moto X 2013—with its perfectly-sized body—next to and on top of the iPhone 6, which has the same-sized display:
Moto X 2013, iPhone 6
Moto x 2013 on top of the iPhone 6
The differences aren't massive, but they're there. The iPhone's need for that physical Touch ID home button really beefs up the bottom bezel, and the top gains as well for symmetry. Not all 4.7-inch phones are created equal.
If you're thinking that's not a huge deal, you're probably right, but the differences really show when you move up to the 5-inch-and-above range. That's where your ability to grip a phone, and how far your thumb can reach, are more important than ever. There's a lot of hubbub that the iPhone 6 Plus and its 5.5-inch display—while great—is freaking huge. It is; it's also big for a 5.5-inch screen phone. Here's the iPhone 6 Plus next to the 5.5-inch screen LG G3:
LG G3, iPhone 6 Plus
LG G3 on top of the iPhone 6 Plus
Where it gets trickier is when you run into phones with even bigger screen sizes but smaller footprints. Take the Galaxy Note 4, for instance. It's got a 5.7-inch screen, so the unconscious logic follows that it's even bigger than the 6 Plus. Nope, pretty much the same size:
Galaxy Note 4, iPhone 6 Plus
Where this matters most so far, though, is the Nexus 6. A six-inch phone sounds huge. It is. But in practice, it's not that much huger than the 5.5-inch iPhone 6 Plus. The Nexus 6 is wider, to be sure, but they're roughly the same height. And it's still much smaller than if you were to just scale the iPhone 6 Plus up to a 6-inch screen:
Nexus 6, iPhone 6 Plus
iPhone 6 Plus on top of the Nexus 6
So as you consider making a jump to a bigger phone, since you don't really have a choice any more, just remember that the toss-off spec of screen size doesn't necessarily indicate how the damn thing will fit in your hand. Knowing a phone's screen size gives you a rough idea of the smallest size a phone could really be in real life, but if your frame of reference for the big'uns is, say, an iPhone 6 Plus, chances are you're imagining everything else as far bigger than it really is.