Im sorry but I dont really understand what you exactly asking for. (my english is not perfect)
Im a single user, I dont want to make a plugin, Im not use any calculator plugin yet, because I did not found the right one.
Still dont have any webshop. We build our new site actually, the webshop will be the next step, but I thinking in a calculator to our visitors, to help them choose the correct product.
Option A: get a programmer to develop the module from sketch what I need
Option B: use an existing plugin which could be use for this situtaion.
Now I asking for the option B. what is the right existing plugin from the wordpress plugin database?
I found one solution, but its for joomla only:
https://andrewart.net/jcg/
