You should also stabilize the coil by dipping the coil in a wire varnish like Glyptol. If you need to connect different segments of the magnet wire together to make the coil, simply scrape off the enamel insulation and solder the different segments together. You do not need to reinsulate the connection. Just make sure that two solder segments do not contact each other. These calculations do not take into consideration the thickness of the wire insulation.
Magnet wire uses enamel insulation which is very thin, so it wont make much of a difference.
Still, after winding the coil, test it with a meter. Use the following table for wire thickness and to determine the DCR of the coil. 1998 Michael LaLena .