Inconsistency when setting TextView font size in code and in resources

You should use setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize); because the documentation of the getDimension method states that it returns a Resource dimension value multiplied by the appropriate metric. which I understand to be the precalculated absolute px value.

That is, use:

tv.setTextSize(TypedValue.COMPLEX_UNIT_PX, getResources().getDimension(R.dimen.text_size_small));