Build ordering calculator with add to cart feature into Wix website

We need an ordering calculator for our Wix site. This needs to be custom coded as there is no app for this in Wix. The calculator serves this purpose: The customer comes to the website to order building materials. They can select the one they need and enter the square foot amount and the calculator will display the total cost per material based on their sq ft. Similar to the calculator at the bottom of this page:

https://www.cletile.com/products/ceramic-white-gloss-subway-7

This must be in Wix.