The difference here is that in the setTextSize(int size) method, the unit type by default is “sp” or “scaled pixels”. This value will be a different pixel dimension for each screen density (ldpi, mdpi, hdpi).
getTextSize(), on the other hand, returns the actual pixel dimensions of the text.
You can use setTextSize(int unit, float size) to specify a unit type. The constant values for this can be found in the TypedValue class, but some of them are:
TypedValue.COMPLEX_UNIT_PX //Pixels
TypedValue.COMPLEX_UNIT_SP //Scaled Pixels
TypedValue.COMPLEX_UNIT_DIP //Device Independent Pixels