How Much Ram Is Used To Cache A CSS file?

[esoptesse]

I'm writing an article on comparisons between using single images, sprites, and base64 in web design.The only issue I'm having is I have no idea how much ram a browser uses to cache a CSS file(which holds the Base64)? So I can make some mathematical comparisons. I thought I read somewhere that it was by lines, but I cannot get any confirmation on this. Or is it just strictly based on file size?Maybe a better question would be, how much ram does a browser use to cache/load text files?Example, for images it is Width X Height X 4bytes. What would it be for a CSS file? Thanks.