Seeking java script creator to make two calculators for website

Diabatix is an engineering firm specialised in generative thermal design. For our customers' ease, we would like to make two tools available on our website: a heatsink calculator and a Reynolds number calculator. We are looking for a web developer who can write the code for these tools, either by creating a plugin or providing us with the code so we can ask our website host to implement it. Below you can two examples. We are looking for something similar.

Heat sink calculator: https://www.allaboutcircuits.com/tools/heat-sink-calculator/

Reynolds number calculator: https://www.omnicalculator.com/physics/reynolds-number