// Calculate ActionBar height
TypedValue tv = new TypedValue();
if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true))
{
    actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());
}

android:paddingTop="?android:attr/actionBarSize"

TypedValue tv = new TypedValue();
    if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true))
        actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());

    if(actionBarHeight ==0 && getTheme().resolveAttribute(com.actionbarsherlock.R.attr.actionBarSize, tv, true)){
            actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());
    }

   //OR as stated by @Marina.Eariel
   TypedValue tv = new TypedValue();
   if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.HONEYCOMB){
      if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true))
        actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());
   }else if(getTheme().resolveAttribute(com.actionbarsherlock.R.attr.actionBarSize, tv, true){
        actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());
   }

TypedValue tv = new TypedValue();

if (getActivity().getTheme().resolveAttribute(R.attr.actionBarSize, tv, true))
{
    int actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,getResources().getDisplayMetrics());
}

private int getActionBarHeight() {
    int actionBarHeight = getSupportActionBar().getHeight();
    if (actionBarHeight != 0)
        return actionBarHeight;
    final TypedValue tv = new TypedValue();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
        if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true))
            actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data, getResources().getDisplayMetrics());
    } else if (getTheme().resolveAttribute(com.actionbarsherlock.R.attr.actionBarSize, tv, true))
        actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data, getResources().getDisplayMetrics());
    return actionBarHeight;
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="Theme.FixedSize" parent="Theme.Sherlock.Light.DarkActionBar">
        <item name="actionBarSize">48dip</item>
        <item name="android:actionBarSize">48dip</item>
    </style>
 </resources>

android:theme="@style/Theme.FixedSize"

int actionBarHeight;
    int[] abSzAttr;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
        abSzAttr = new int[] { android.R.attr.actionBarSize };
    } else {
        abSzAttr = new int[] { R.attr.actionBarSize };
    }
    TypedArray a = obtainStyledAttributes(abSzAttr);
    actionBarHeight = a.getDimensionPixelSize(0, -1);

?attr/actionBarSize

public static int getThemeAttributeDimensionSize(Context context, int attr)
{
    TypedArray a = null;
    try{
        a = context.getTheme().obtainStyledAttributes(new int[] { attr });
        return a.getDimensionPixelSize(0, 0);
    }finally{
        if(a != null){
            a.recycle();
        }
    }
}

public int getActionBarHeight() {
        int height;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            height = getActivity().getActionBar().getHeight();
        } else {
            height = ((ActionBarActivity) getActivity()).getSupportActionBar().getHeight();

        }
        return height;
    }

public int getActionBarHeight() {
    final TypedArray ta = getContext().getTheme().obtainStyledAttributes(
            new int[] {android.R.attr.actionBarSize});
    int actionBarHeight = (int) ta.getDimension(0, 0);
    return actionBarHeight;
}

public static int getActionBarHeight(Activity activity) {
        TypedValue typedValue = new TypedValue();

        int attributeResourceId = android.R.attr.actionBarSize;
        if (activity instanceof AppCompatActivity) {
            attributeResourceId = R.attr.actionBarSize;
        }

        if (activity.getTheme().resolveAttribute(attributeResourceId, typedValue, true)) {
            return TypedValue.complexToDimensionPixelSize(typedValue.data, activity.getResources().getDisplayMetrics());
        }

        return (int) Math.floor(activity.getResources()
                .getDimension(R.dimen.my_default_value));
    }

var styledAttributes = Context.Theme.ObtainStyledAttributes(new[] { Android.Resource.Attribute.ActionBarSize });
var actionBarSize = (int)styledAttributes.GetDimension(0, 0);
styledAttributes.Recycle();

int[] location = new int[2];
  mainView.getLocationOnScreen(location);
  int toolbarHeight = location[1];

The action bar now enhanced to app bar.So you have to add conditional check for getting height of action bar.

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
   height = getActivity().getActionBar().getHeight();
 } else {
  height = ((ActionBarActivity) getActivity()).getSupportActionBar().getHeight();
}

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
           ....
           int actionBarHeight = getActionBar().getHeight());
           .....
    }

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

int actionBarHeight = toolbar.getLayoutParams().height;