How to create a coil (self) knowing the inductance ?

[TanguyClt]

Hello I search for a formule with witch I could create a 0.32mH and a 2.91mH coil. I just need to know how many spires and what diameter of the cable must I take.
Thanks

 

[Elvee]

There are tables, formulas and graphics for that, but nowadays it is far simpler to use one of the many on-line calculators available: here is one example among many:
Coil32 - Multilayer coil calculator
You can cross-check the results using two or more of them

Note that you have to decide the wire diameter: it will determine the losses and the maximum possible current

 

[PRR]

Google "coil inductance calculator"

Coil Inductance Calculator
https://www.eeweb.com/tools/coil-inductance
Air Core Inductor Designer / Calculator
Coil32 - Multilayer coil calculator

 

[Enzo]

When I had my shop, I sometimes needed a 2.9mH coil for a speaker. I would buy them from Parts Express, but they only came in even values. SO I bought a 3mH coil, connected it to my L meter, and unwound some turns until it went down to 2.9.

 

[TanguyClt]

Ok thanks a lot for answering me it realy help me. I will probably create it myself because I do not have inductometer so I cannot use a coil and unwound it.