如何在给定html文件的情况下确定html表的大小（以像素为单位）

I have a html file that has various html tags in it. This html also has a bunch of tables in it. I am processing this file using python. How do I find out what the size (length x width in pixels) when it is rendered by a browser (preferably chrome or firefox)? I have a html file that has various html tags i