Get physical size of screen in flutter

Question

I am building a flutter application that needs precise measurements of the screen in cm / inches.

According to the docs,

By definition, there are roughly 38 logical pixels per centimeter, or about 96 logical pixels per inch, of the physical display. The value returned by devicePixelRatio is ultimately obtained either from the hardware itself, the device drivers, or a hard-coded value stored in the operating system or firmware, and may be inaccurate, sometimes by a significant margin.

I have tried using these ratios in my application but they are not even close.

Is there a way to accurately calculate the dimensions of the screen?

Answer 1

Flutter's pixel coordinates are given in logical pixels rather than physical pixels. However, MediaQuery will give you the conversion ratio.

var mediaQuery = MediaQuery.of(context);
var physicalPixelWidth = mediaQuery.size.width * mediaQuery.devicePixelRatio;
var physicalPixelHeight = mediaQuery.size.height * mediaQuery.devicePixelRatio;

(Note that this code can only be run in a place where a BuildContext object is available, such as a build method or a StatefulWidget's companion State class.)