Center text android button

There are three systems to consider. The xml layout designer, the simulator, and real phone. The text in the button if you specify gravity="center" will look like this. In xml layout designer it will look like the leftmost letter is in the center of the button but the rest of the letters are to the right. (looks incorrect) In simulator, the text shows well in the center. (correct) In phone, the text shows well in the center. (correct)

It's easy peasy, you can put this:

android:textAlignment="center"

Your existing layout cannot hope to center the text due to the sizes you have selected. You've set the button height to 30dp and your textSize is 50dp, and for whatever reason, Android is unable to deal with that and center the text. If you make your button larger or your text smaller you'll see that the centering works.