How is cell phone screen size measured, cell phone screen sizes in pixels
Cell phone screen size is measured diagonally as shown in the image here. This diagonal screen size measurement of phone screens is given in inches. The standard screen sizes of cell phones available today can be anywhere from 4 inches to 6 inches diagonally. Just 2 years ago the largest phone screen size was about 5.5 inches diagonally. Phones with over 5.5 inch screen were called a phablet – a cross between a phone and a tablet. Now this has changed, the size of a phablet now starts at 6 inches diagonally.
The pixel size measurement of mobile phones are the number of pixels on the phone screen in the X and Y direction, that is the number of pixels in the horizontal direction into the number of pixels in the vertical direction.
How to measure mobile screen size in inches
To know how the size of cell phone screen, you must measure the phone screen size in inches between to diagonally opposite corners. For example, measure from bottom left corner of screen to top right corner of phone screen. This is the diagonal measurement of cell phone screen as shown in the image here.
The screen size is measured in inches, but in countries which have the metric system of measurement, it will be given in centimeters. To convert inches into centimeters, the inch size is multiplied by 2.54, since 1 inch equals 2.54 centimeters. The phone in the image has a screen size of 4”, which when converted to centimeters equals 10.2cms.
What is pixel size of phone screen
Pixels are the smallest blocks which make up the screen. The word ‘Pixel’ is an abbreviation of ‘Picture Element’. When the pixels are densely packed together, you get a much clearer picture. Cell phone screen sizes in pixels are normally represented by two numbers, for example, in the image here, the Cell phone screen sizes in pixels is 720×1080. This means that there is 720 pixels in the ‘X’ axis or horizontally and 1080 pixels in the ‘Y’ axis or vertically.
Some of the higher end cell phone resolutions today are Full HD=1080×1920 pixels, Quad HD=1440×2560 pixels and 4K Ultra HD=2160×3840 pixels.
What is PPi pixel density in phones
PPI stands for Pixels Per Inch and is a measure of or how tightly packed the pixels in a mobile cell phone are. PPI is actually the Pixel Density of the display screen of the mobile cell phone. The PPI of mobile cell phone screens is got by dividing the number of pixels along either the vertical or horizontal axis by the length in inches of that side.
We can calculate the length of any side of a phone screen from the diagonal size of the phone screen and the pixel ratio between X and Y axis. Thus we can calculate the sides of a 4 inch phone display screen to be 2.63 and 3.945 inches. The PPI thus works out to 273 (720/2.63 or 1080/3.945).
Right now the Sony Xperia XZ is the highest PPi pixel density mobile phone with a PPI of 806. The Sony Xperia XZ is the only Ultra HD 4K screen cell phone available now. The Apple iPhone 7 with Retina 5.5-inch HD display of 1920×1080-pixels has only 401 PPi. The Samsung Galaxy S8 has a 5.8″ Quad HD+ Super AMOLED screen with a 2960×1440 pixel resolution and 570 PPi.
Best cell phone screen type: LCD or AMOLED
The two most popular types of phone screens in the latest smartphones are the IPS LCD display screen or Super AMOLED display screen. The full form of ‘LCD’ is Liquid Crystal Display and ‘AMOLED’ is Active Matrix Organic Light Emitting Diode. These are without doubt the best smartphone display types to date. It is difficult to decide which cell phone screen type is best. We compare the advantages and disadvantages of IPS LCD and Super AMOLED cell phone display screens in the following table chart.
| Criteria | Super AMOLED cell phone screen | IPS LCD cell phone Screen |
|---|---|---|
| Picture Quality | The picture quality of both Super AMOLED and IPS LCD screens are very good. It is very difficult for human eyes to judge whether the picture on a Super AMOLED or IPS LCD screen cell phone has a better picture | Both IPS LCD and Super AMOLED display cell phones have super resolutions and very high quality picture and only advanced instruments can make out the difference between the picture quality of IPS LCD and AMOLED cell phone screen mobiles |
| Picture Brightness | The pixels in a Super AMOLED mobile cell phone screen are self illuminating and does not require a backlight. There is a limit on how bright Super AMOLED screens can be and so out in the sunshine Super AMOLED cell phone screens are difficult to see, but indoors they are excellent with better contrast ratios than the IPS LCD screens. | Since cell phones with IPS LCD screens has a backlight, the brightness of which can be adjusted, so outdoors in bright sunshine, IPS LCD screen phones are easier to see than the Super AMOLED screens. |
| Thickness of Phone | Cell Phones with Super AMOLED screen are thinner than phones with IPS LCD Screens since Super AMOLED screen works without a backlight. | Cell phones with IPS LCD screens tend to be slightly thicker since they require a backlight. But the newer IPS LCD screens have become very thin. |
| Phone Models Screen Type | Samsung Note 8 and Galaxy S8, OnePlus 5 | Apple 7 and 7 Plus, Sony Xperia XZ Premium 4K screen |