Regarding the Coil Wrapping calculator:
How is Leg Length measured? it says “total per coil,” does this mean the sum of both legs on either end of a coil? where does the ‘leg’ start?
Here is a very professionally drawn illustration of a coil, with a red line through the center.
So if both legs are the same length (as is usually the case), measure one of the legs from the center of the helix to the point where the leg connects to the post in the atomizer. Then double that number.