Automations by themselves cannot perform calculations, so you could not do this using only automatons. You can use formula fields to do the calculations, and then have the automation copy the result from the formula field to an editable field. This could result in having an additional 30 formula fields. (If you do not want the additional 30 formula fields, you would need a script or a third party automation system that can perform calculations.)
However, the main trick here is determining the proper trigger for the automation. Will the user be entering all 15 measurements in one set of fields, and then trigger the automation (with a single-select field, checkbox field, or interface button element) to populate the other set of 15 fields? This is the most doable.
Other work flows get tricky. For example, I do not recommend having an automation that triggers based on when a field is updated, as the automation can trigger prematurely while the user is still in the process of typing. This can cause you to use up a lot of automation runs unnecessarily, and make things very confusing, because you would need a lot of helper fields so that the automations could know who did the update (the user typing or an automation).
