Tuning Hammer Spring Questions

Hi AGN. I need some input from the professionals please. This is somewhat new territory for me so appreciate the understanding.

I would like the lightest possible hammer spring weight that will allow everything to function properly. Is there a way to calculate necessary hammer spring weight to have a good starting point Or is it all trial and error?

Also, how do you measure spring weight for compression?

I appreciate any information I can get on this subject!