Is there a known macro or a easy way to make one that could calculate easy surface like width x height in mp ?:)

Hello,

Asking whats already in the title of the question : does anyone known of a macro that or how to make one that calculates width x height and if the result could be displayed in mp ?

For example : I have a rectangle with w: 800mm and height 600mm and what I do is calculate this manualy 0.8m x0.6m = 0.48mp. If there's a macro that could maybe display this when i click on the object that would be such a time saver, as maybe the curve lenght works

Thank you in advance !