How to determine the screen width in terms of dp or dip at runtime in Android?

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I need to code the layout of the android widgets using dip/dp (in java files). At runtime if I code,

int pixel=this.getWindowManager().getDefaultDisplay().getWidth();

this return the screen width in pixels (px). To convert this to dp, I coded:

int dp =pixel/(int)getResources().getDisplayMetrics().density ;

This does not seem to be returning correct answer. I made the emulator of WVGA800 whose screen resolution is 480 by 800. When the run the emulator and let the code print the values of pixel and dp, it came to 320 in both. This emulator is 240 dpi whose scale factor would be 0.75.

13 Answers

2022 Answer simplified for Kotlin:

val widthDp = resources.displayMetrics.run { widthPixels / density }
val heightDp = resources.displayMetrics.run { heightPixels / density }

Or as one-liner:

val (height, width) = resources.displayMetrics.run { heightPixels/density to widthPixels/density }

Answer in kotlin:

  context?.let {
        val displayMetrics = it.resources.displayMetrics
        val dpHeight = displayMetrics.heightPixels / displayMetrics.density
        val dpWidth = displayMetrics.widthPixels / displayMetrics.density
    }

Get Screen Width and Height in terms of DP with some good decoration:

Step 1: Create interface

public interface ScreenInterface {

   float getWidth();

   float getHeight();

}

Step 2: Create implementer class

public class Screen implements ScreenInterface {
    private Activity activity;

    public Screen(Activity activity) {
        this.activity = activity;
    }

    private DisplayMetrics getScreenDimension(Activity activity) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        return displayMetrics;
    }

    private float getScreenDensity(Activity activity) {
        return activity.getResources().getDisplayMetrics().density;
    }

    @Override
    public float getWidth() {
        DisplayMetrics displayMetrics = getScreenDimension(activity);
        return displayMetrics.widthPixels / getScreenDensity(activity);
    }

    @Override
    public float getHeight() {
        DisplayMetrics displayMetrics = getScreenDimension(activity);
        return displayMetrics.heightPixels / getScreenDensity(activity);
    }
} 

Step 3: Get width and height in activity:

Screen screen = new Screen(this); // Setting Screen
screen.getWidth();
screen.getHeight();

In the new world of Compose on one line

val (height, width) = LocalConfiguration.current.run { screenHeightDp.dp to screenWidthDp.dp }

This is a copy/pastable function to be used based on the previous responses.

  /**
     * @param context
     * @return the Screen height in DP
     */
    public static float getHeightDp(Context context) {
        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        float dpHeight = displayMetrics.heightPixels / displayMetrics.density;
        return dpHeight;
    }

    /**
     * @param context
     * @return the screnn width in dp
     */
    public static float getWidthDp(Context context) {
        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        float dpWidth = displayMetrics.widthPixels / displayMetrics.density;
        return dpWidth;
    }

If you just want to know about your screen width, you can just search for "smallest screen width" in your developer options. You can even edit it.

Try this:

Display display   = getWindowManager().getDefaultDisplay();
Point displaySize = new Point();
display.getSize(displaySize);
int width  = displaySize.x;
int height = displaySize.y;
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