how check the font size in IE and NS

hello All,
How can I see the default font size in the IE and NS browser. I can see the font face in the options/preference. Does this depend on the Text size option we see in View( small, Medium ... etc) or the font size we set in the computer properties.
Thanks

I am not really sure where it takes it from, also, in IE there is an ability to override styles provided by web page with some predefined ones.
But back to your question
Create a hidden span with some text inside and check that span height (set margins to 0, etc). It will give you font size in pixels.