Getting the default font size of a multiline TextView in Android

I want to have a font-size preference in percentage relative to the default font-size, 开发者_高级运维so I need to get the default font-size for a TextView.

How do I get the default font-size of a TextView?

This will return the value in pixels within a context:

float size = new TextView(this).getTextSize();

TextView txt = (TextView) findById(R.id.text);
float size = txt.getTextSize();

This should do it on an existing one