How to determine device screen size category (small, normal, large, xlarge) using code?

You can use the Configuration.screenLayout bitmask.

Example:

if ((getResources().getConfiguration().screenLayout &     Configuration.SCREENLAYOUT_SIZE_MASK) ==         Configuration.SCREENLAYOUT_SIZE_LARGE) {    // on a large screen device ...}

The code below fleshes out the answer above, displaying the screen size as a Toast.

//Determine screen sizeif ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE) {    Toast.makeText(this, "Large screen", Toast.LENGTH_LONG).show();}else if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_NORMAL) {    Toast.makeText(this, "Normal sized screen", Toast.LENGTH_LONG).show();}else if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_SMALL) {    Toast.makeText(this, "Small sized screen", Toast.LENGTH_LONG).show();}else {    Toast.makeText(this, "Screen size is neither large, normal or small", Toast.LENGTH_LONG).show();}

This code below displays the screen density as a Toast.

//Determine densityDisplayMetrics metrics = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(metrics);int density = metrics.densityDpi;if (density == DisplayMetrics.DENSITY_HIGH) {    Toast.makeText(this, "DENSITY_HIGH... Density is " + String.valueOf(density), Toast.LENGTH_LONG).show();}else if (density == DisplayMetrics.DENSITY_MEDIUM) {    Toast.makeText(this, "DENSITY_MEDIUM... Density is " + String.valueOf(density), Toast.LENGTH_LONG).show();}else if (density == DisplayMetrics.DENSITY_LOW) {    Toast.makeText(this, "DENSITY_LOW... Density is " + String.valueOf(density), Toast.LENGTH_LONG).show();}else {    Toast.makeText(this, "Density is neither HIGH, MEDIUM OR LOW.  Density is " + String.valueOf(density), Toast.LENGTH_LONG).show();}

Jeff Gilfelt's answer as a static helper method:

private static String getSizeName(Context context) {    int screenLayout = context.getResources().getConfiguration().screenLayout;    screenLayout &= Configuration.SCREENLAYOUT_SIZE_MASK;    switch (screenLayout) {    case Configuration.SCREENLAYOUT_SIZE_SMALL:        return "small";    case Configuration.SCREENLAYOUT_SIZE_NORMAL:        return "normal";    case Configuration.SCREENLAYOUT_SIZE_LARGE:        return "large";    case 4: // Configuration.SCREENLAYOUT_SIZE_XLARGE is API >= 9        return "xlarge";    default:        return "undefined";    }}