Not sure if something like this is available - but I need a solution for calculations with logic. Actually, the calculations are static numbers. It’s probably easier to show you what I’m looking for than trying to explain. Have a look at the logic on this page: https://smartchoicemri.com/price-calculator/
The Calc stack should do the trick https://stacks4stacks.com/calcstack/
Joe’s Pi stack is just about the only calc stack you need, it uses JS maths so you can build some really complex calculations in it with ease.
Here’s a couple of my tests:
The Demo on Joe’s site is quite good (I may have had a hand in it :) )
1LD also have a calculation stack called Formula.
However Joe’s Pi stack is a lot more powerful, the only Thing to note is that it relies on input from other form stack elements as it doesn’t have any of its own…though somehow I think that won’t be a problem for you Dave