How to calculate PPi Pixel Density of Phone Screen
What is PPi Pixel Density in mobile? The PPi Pixel Density meaning in a phone is how close the pixels are packed together on the phone screen. PPi means Pixels per inch and is relation between screen size and resolution of the phone. You can easily calculate Smartphone PPi Pixel Density, by first calculating the length and breadth of the sides of the phone screen from the diagonal phone size using the Pythagoras method theorem as shown in the phone PPi calculation here.
How to calculate PPi Pixel Density for a 4 inch diagonal screen with a screen resolution of 720x1080 pixels is shown here. First the width and height of the phone screen is worked out as follows:
The PPi Pixel Density calculator of cell phones shown here demonstrates how the Pythagoras method is used to calculate the dimensions of the sides of a 4 inch screen. Note that we assume the height to be 'h' and since the ratio of the width 'W' to height is 1080:720, the height will be W x 1080/720 or h=1.5W.
As shown in the calculation here, using the 4 inch diagonal screen size of the phone, we get the dimensions of the sides of the phone screen as width=2.63 inches and height as 3.945 inches. Now we will use this result to calculate the pixels per inch or PPi of the mobile phone.
PPi of mobile phones
The PPi of mobile phone screens are calculated by dividing the number of pixels along either the vertical or horizontal axis by the length in inches of the corresponding side. Here to find the PPi we do the calculation: divide 720 pixels by 2.63 inches or 1080 pixels by 3.945. The result we get in either case is 273.764 ppi.
Highest PPi Phones, best PPi phone
The human eye cannot easily distinguish the difference in PPI when the figure reaches a saturation point of about 300 PPi. So the minimum PPi for a smartphone should be about 300 PPi, but the best PPi pixel density phone can be of a higher pixel density.
Having a PPi of more than 300 ppi will not make that much of a difference to normal human eye vision when reading text on a phone screen, but graphics and pictures will stand out much more clearly in phones with higher PPi pixel Density.
Phones with higher PPi pixel density is one of the main causes of cell phone battery drain, since more number of pixels means more power eaten from the battery. Also a phone with more than 300 PPi pixel density means the phone becomes more expensive with not that much additional benefits. Going over this 300 PPi is at the expense of battery life. So Apple iPhones may be striking a balance between battery life and high PPi numbers.
As of date the highest PPi Smartphone in the market is the Samsung S6 with 571 pixels per inch. Because of the big size of the Galaxy S6 it can have a bigger battery to compensate for the battery drain due to the high PPi screen. The Samsung Galaxy phones also have more energy efficient Super AMOLED Screens compared to the iPhones with IPS LCD screens, so the even with the higher PPi screen density, the Galaxy phones do not drain battery that fast.
iPhone 6 screen Vs Galaxy S6
Many wonder why iPhone screen resolution is less than Samsung Galaxy phones and why Apple iPhones does not try to have higher resolutions than the Samsung Galaxy phone range. Samsung Galaxy and other Android Phones which have PPi of over 500 whereas iPhones lag behind with only about 400 PPi.
The reason, many say, could be attributed to Steve Jobs philosophy that there is no point in cramming higher pixel densities into displays if the human eye cannot perceive them and Steve Jobs set that optimum number of pixels at about 300 PPi.
But higher screen resolutions than 300 does make the phone screen appear superb and we feel that the reason Apple is not having higher resolution phone Screens could be due to the fact that the IPS LCD screen of the iPhones drain battery faster than the AMOLED screens of Samsung Galaxy.
One of the ground rules of mobile smart phones is that they should last at least 24 hours on a single charge with moderate heavy usage. So, may be, iPhone battery cannot last 24 hours at higher screen resolutions, because of the battery drain of LCD screens at higher resolutions. We are not sure of this, but with Samsung Galaxy S6 and Samsung Galaxy Note-4 having such high resolutions of 571 and 515 PPi respectively compared to iPhone 6+ and iPhone 6 at 401 and 326 PPi respectively is a huge difference, 25% more than the iPhone resolutions. We cannot imagine Apple iPhones losing the lead in the screen resolution battle, after all it was Apple who introduced the concept of Retina Displays.
Best Pixel Density phones 2015
Which mobile phone has the highest pixel density? We have a table below of smartphone PPi ranking, listing the best pixel density phones of 2015. Top best smartphones of 2015 having best smartphone PPi rating in the world are compared with each other. The chart below also lists the smartphone screen resolutions and smartphone PPi rating, thus it serves both as a smartphone screen resolution chart and also as a smartphone screen PPi chart. The smartphone PPi ranking in the chart below is in descending order and has smartphones with the highest PPi rating on top.
|Model||Screen Size Inch||Screen Size Cms||Resolution Pixels||Pixel Density PPi|
|Samsung Galaxy S7||5.1||12.95||1440 x 2560||571|
|LG G3||5.5||13.97||1440 x 2560||534|
|Samsung Galaxy Note 5||5.7||14.48||1440x2560||515|
|Nexus-6||5.96||15.14||2560 x 1440||493|
|HTC One M8||5||12.7||1080 x 1920||441|
|Samsung Galaxy S5||5.1||12.95||1080x1920||432|
|Sony Xperia Z3||5.2||13.21||1080x1920||424|
|iPhone-6 Plus||5.5||13.97||1080 x 1920||401|
|Lumia 1520||6||15.24||1080 x 1920||367|
|iPhone-6||4.7||11.94||750 x 1334||326|