Produce interactive page using div fields to be added to website

We currently use an Excel spreadsheet to calculate frame lengths (sample provided but only works on the latest Excel). The calculations are simple addition. We are wanting fields overlaying the image that will do the calculations as shown in the spreadsheet to allow our customers to add their own figures to produce a frame length figure.
Criteria:
HTML/CSS/JavaScript
DIV not table construction
Div's to have their own individual classes
Have defaults in the interactive fields
All fields required and validated with error message.
Be responsive
We will supply:
The base image (we can edit as required)
To be made standalone and we will add to static cms page on our website.
Website: https://www.unicycle.co.uk
Similar example on website: https://www.unicycle.co.uk/calculator