Years ago, I worked with a doctor that specialized in sports medicine and physical therapy. He asked me to create a bespoke grip strength calculator that he could use and present to patients of his. I used charts and data available from the NIH to do the math and meet the task requirements. I wrote this in vanilla JavaScript and in a way that it could be embedded in nearly any site that allowed custom HTML. This was initially going to be embedded in a Magento content page and it worked out well.