I just discovered through another post that I can upload files to forums. So, attached is a simple and helpful spring rate calculator I made a while back and use to determine the spring rate of shock springs and some fork springs using only calipers an the calculator. You'll need calipers to make this practical, as the wire diameter especially is quite sensitive to error, being to the 4th power in the equation.

I've done some experimentation to tweak the equation to more closely match the spring rates of parts with provided spring constants.

Anyway, it's yours to use as you please. Open to suggestions on how to improve it.

For those of you in metric countries, I provide a conversion to kg/mm in the output. Sorry, we still use pounds and inches in my little corner of the world. You can alter the formulas in spreadsheet to flip the units.

 

Very nice thank you for posting!