Generally, it is cheaper to buy inductors. If you want to make one, I suggest using a pot core type. Ferroxcube has design guides and charts. Search this site for a link to their pdf version named ferrite hand book.pdf
what is your application?
please be careful!
for inductor design, two current rating is required:
1.peak current (Imax) which determines Bmax of core material
2.RMS of current which determines wire diameter
the relation between two values is determined by waveform of inductor current .
Now the adlab library includes inductor and transformer design where single layer, multilayer, toroidal, circular, spiral, frame and parallel line inductor can be designed. The demo version can be used for 100 times.
The download link for the adlab version 2.5 (latest version) says that it has been removed from the download site. I have e-mailed Stephan Weber (who writes this program) to report this problem.
Attached is the coils program from version 2.4. I am not sure if it will run separately from the rest of the utiilities. Would someone download this and try it out and report on its working by itself or not in the demo mode. Since no files can be downloaded from his site attached are also the full demo versions of his products. I personally find the ad lab plus well worth the $40 fee.