Woocommerce custom field calculation


currently I am trying to build a small online shop for our printing company. I am trying to get this done with woocommerce. I am using variations to get options like A4, A3, A2 or b/w, color. Furthermore I bought the plugin Extra product options to have a multifile upload and checkboxes,ect.

But what if someone has different paper dimensions like 500x200mm? How can I add a field with length and height, which then multiplies itself with our sqm price?
E.g.: 0,5m x 0,2m *5,20= 0,52 * product options.

Is there a way to get this done?