Summary

With the emergence of phones with screens on board, it is time to permanently silence a received idea: the diagonal of the screen of a smartphone is not enough to assess its size!Or how "a 5.5 inch phone" can be more compact than a "4.7 -inch smartphone".

Since the advent of the modern smartphone with the iPhone in 2007, we have gotten into the habit of expressing the size of a smartphone by the diagonal of its screen.Over the years, smartphones have seen the diagonal of their screen grow to accommodate the new uses created by our favorite applications, more and more navigation and video reading and less and less telephone calls.

5 and 5.5 inches: new standards

The market subsequently stabilized around two sizes of screens, the flagships of each brand all had a diagonal around the 5 inches and they often had a "phablet" variation with a screen of more than 5.5 inches.We are talking about the Galaxy S7 with the Galaxy S7 Edge, the iPhone 7 with the iPhone 7 Plus, or the Lumia 950 with the Lumia 950 XL, or more recently of the Huawei P10 and P10 Plus, the examples are numerous.

For several reasons, expressing the size of a smartphone with the diagonal of your screen is a bad idea.She can even deceive the consumer who thinks of buying a small smartphone when he actually buys a large and poorly designed or technologically trained smartphone.Explanation.

The diagonal does not take into account the margins

The first problem is that the diagonal of the screen only expresses the size of the screen.Yes, said how obvious it is, but it means that it does not take into account the margins around the screen.

However, that would not be a problem if all the manufacturers reached the same degree of integration of their components and screens in their smartphones, but this is not the case.Apple has long been the worst student on the market here and the one who gained the most to maintain confusion between sizes of the smartphone and diagonal.

The Huawei Mate 9 (6 inches) vs the iPhone 8 Plus (5.5 inches)

A glaring example is a comparison between the iPhone 8 Plus (5.5 inch screen) and the Huawei Mate 9 (5.9 -inch screen).An iPhone 8 Plus user could be frightened at the idea of using a Huawei Mate 9 and yet the Huawei Mate 9 is 1.5 mm less in height and 0.8 mm more in width.We see that Huawei offers here much thinner borders than Apple.

Finally, there is also the case of the so -called “edge” screens like that of the Galaxy S8 which overflows on the sides of the smartphone.Except when the software takes it into account, to display a notification for example, we cannot really say that these screen surfaces are useful, apart from an aesthetic aspect.Yet these edges artificially grow the diagonal of the screen of a smartphone with an equivalent box size.

Watch out for ratio differences

To offer screens with fewer borders, the manufacturers have chosen to modify the display ratio of their screens.Forget, on 16: 9, a standard of the market, Apple now uses 19.5: 9 for its iPhone X, Samsung uses 18.5: 9 on its Galaxy S8 or its Galaxy Note 8 and other manufacturers use moreIn addition often on 18: 9 (or 2: 1).Again, indicate only the diagonal of a screen does not account for the size of the smartphone if you do not give its display ratio.

Let's take up the 2017 Apple smartphones range, the Californian manufacturer is the only one to dare to offer a high -end smartphone as old as the iPhone 8, which allows a comparison with the iPhone X which represents the future of the brand.

The 5.8 -inch iPhone X screen is actually a rectangle of 13.4 x 6.2 cm, while the iPhone 8 Plus screen measures 12.2 cm by 6.8 cm.On the surface, this represents 83.08 cm² for the iPhone X against 82.96 cm² for the iPhone 8 Plus.The two surfaces are therefore very close, despite a difference of 0.3 inch on the diagonal expressed without taking into account the display ratio.

The need to find a unique criterion

There is an analogy to do here with the pixel definition of a screen and the pixel density.To compare it with the competition, it is fairer to note the resolution of a pixel screen by inch than to simply indicate its definition in pixels, since the latter gives no information without knowing the size of the screen.

This is what Apple did when the brand created the term "retina" to design the iPhone 4 screen which benefited from a better definition with equivalent diagonal, and therefore better densitypixel.

For the subject that interests us today, the solution chosen by the industry seems to be expressing the surface rate occupied by the screen on the front.

This measure would penalize smartphones with a small screen and a large box and promote manufacturers who apply to better integrate screens.

Should we say definition or screen resolution?If the two elements are very strongly linked, they are not quite similar.We explain how to make the difference.Read more

Borderless or foldable screen: a generalized problem

If in 2016, it was still possible to get an idea of the size of a phone with the diagonal of your screen, with a few inch commas, the situation became more complex in 2017 with the emergence of the edges edge toedge and changes in display ratio.

In the coming years, smartphones with foldable screens should also arrive on the market.Samsung would plan to get one out of it next year.In this situation, as we could express the size of a smartphone with the diagonal of a screen that folds in half?The diagonal should no longer be a criterion.

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