Version: 2017.4
public static float dpi ;

説明

スクリーン/デバイスの現在の解像度(読み取り専用)

This is the actual DPI of the screen attached or physical device running the application. May return 0 if unable to determine the current DPI.
Note that on Android this returns densityDpi which is a logical bucket containing a range of dpi values. If you need a more precise dpi value, see this forum thread.