Basics of Smart mobile cell phones

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:

pixel density calculator or cell phone screen PPi calculator shows how to calculate PPi of a phone screen

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 2018

Which mobile phone has the highest pixel density in 2018? We have a table with the PPi of 2018 phones with highest PPi screens. Top best mobile phones of 2018 having the best screens with highest PPi in the world are compared with each other. The chart table below also lists the mobile phone screen resolutions, their aspect ratio and PPi.

Phones with best screens 2018
Mobile Phone NameScreen SizePixel SizeAspect RatioPpi
iPhone-84.7 inch1334x75016 by 9326
iPhone-8 Plus5.5 inch1920x108016 by 9401
iPhone-X5.8 inch2436x112516 by 9458
Samsung Galaxy S85.8 inch2960x144018.5 by 9572
Samsung Galaxy S8 Plus6.2 inch2960x144018.5 by 9529
Samsung Galaxy Note-86.3 inch2960x144018.5 by 9521
Google Pixel 25 inch1920x108016 by 9441
Google Pixel 2 Plus6 inch2560x144016 by 9538
Sony Xperia XZ Premium5.5 inch3840x216016 by 9801

Compare Mobile Cell phone prices online before buying

The best way to buy a mobile cell phone is to first see all the phones that are available online. These online companies offer some great discounts on the latest models, especially for phones where new models are going to be announced soon. Once you study all the available models and prices of mobile cells online, you can safely do your shopping in the local stores. In case you cannot find better prices, you can confidently buy online from or Flipkart, because they are the leading online retailers in India. Both these online stores in India have reputation to keep, and they will make sure that you get the original latest versions and also have very customer friendly after sales service.

For online shopping of mobile phones, here are some links: Special offers on Mobile Phones in India Buy from

Best selection of Cell Phones and accessories in USA from Buy from

Below are Links to all pages on this website