Feedback from people doing the same kind of sizing work is the best way to improve the calculators. Three things help most:
A result differs from what you expected
Useful details are the address of the calculator, your input values and the value you expect - ideally with the source you calculated against. Every calculator offers a „copy link“ action that encodes your inputs, so I see exactly the same state you do.
A calculator is missing
Tell me which calculation you need and which source it should follow. A new calculator is only built with a worked example to verify the result against - if you can contribute one from a reference book, that shortens the path considerably. Why this rule exists is explained under method.
A standard has changed
Editions move on, and I do not always hear about it first. A pointer to a new edition is very welcome.
I answer messages myself, usually within a few days. Please understand that I cannot take on the sizing of specific components - that would be an engineering service and is something other than a tool.