[ozzythecat]

Is your goal to turn your calculators into web interfaces? Are you wanting to learn how to do that?

If the goal is purely providing something functional to others on the internet, just create a simple page. Describe your calculators. Add links to download your calculators as excel spreadsheets.

No need to over complicate and build a spreadsheet in a browser.

If you don’t want to do that, just create some HTML pages with forms and use some JS to chain together input boxes and spit out a calculation.

Many of the suggestions here will take you the route of complicated layers of abstraction. Unless your goal is to learn these abstractions, you can avoid that complexity.