Moderator note: Tom has worked to post his Excel document onto a Dropbox link for all to use. He's provided this updated content for the original post:
I've put a spreadsheet together to help you determine your available weight capacities (or you print it out for your next weigh station stop).
You'll have to do your own legwork to get your TV & TT specs in the appropriate cells, but then just plug in your actual weight values as per the Weighing Procedure instructions at the bottom, and the sheet will do the rest of the work for you.
Vehicle Weight Calculator.xlsx
I hope this has value to folks, especially the rookie campers among us like myself.
Comments, suggestions, and/or corrections welcome. Safe towing!