I seen it online some where, there is a chart that shows, ohms and the of wraps and diameter of the drill bit needed to get the ohms you want. I want to build to my RDA's above sub ohms, and need to figure out what I need to do it, I have tried 1/16, 5/64, 3/32, and 24 gauge, 26 gauge, 28 gauge and keep coming out with sub ohm coils, for example I use twisted 28gauge in my Kayfun with 10wraps on a 5/64 drill bit and it comes out 1.2 ohm which is perfect for a Kayfun, use two of those same coils or non-twisted 28gauge you come up with a .6 ohm build and it is way to warm for me. If I use 24 gauge with a 5/64 bit and 8 wraps and two coils its .3 ohms way too hot, same with the 26 gauge, they all come out way too low. I prefer flavor over huge clouds, plus I got some DNA30 devices coming so I want to stay over 1.ohm and adjust the wattage to bring out the flavor even more.