I’d agree with others, I don’t think you need a custom “app”, you just need to upgrade your spreadsheet skills. That’s probably the easier path here.
Theoretically you could make your components variables and just point your sheets doing the calculations at those variables. So you just change value of your variable, and your sheet re-does the calculation.
The only reason I’d recommend doing something custom is if you’re building a client-facing form. But even then, a simple Google Form that points at Google Sheets would work.