I am designing a coil which will have 2100 turns of 30AWG wire. The bobbin diameter is 1.045" and the length is 1.28" From my calculations I will use about 8,420 inches of wire. I tried an online calc but they did not take into account that the wire I am using has a heavy insulation so it's diamter is about .0115". As we know things is the real world are usually somewhat different. My question is how much of an error tolerance I should expect in terms of wire length for the 2100 turns? And should I expect to use more or less wire than calculated? Any help/suggestions would be greatly appreciated.