 <p>It's just an assumption, but according to <a href="http://developer.android.com/reference/android/app/Fragment.html#Lifecycle" rel="nofollow">Android Developers</a>:</p> <blockquote> <p>onStart() makes the fragment visible to the user (based on its containing activity being started).</p> </blockquote> <p>So width and height will be calculated only <strong>after</strong> your fragment will become visible.</p> <p>But, maybe, I'm not right.</p>