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Calculation of Inductance of an Air Cored coil

The following formula calculates the inductance of an air cored coil.
It is ok up to 30MHz but should be used only as a rough guide above that.

L= ( d2 x n2 )  /  (18d + 40l )

where:- L is the inductance in micro Henrys,
d is the coil outside diameter in inches (form diameter plus the wire),
l  is the coil winding length in inches, and
n is the number of turns.

Since this page uses Java, you will need to enable scripts or ActiveX to run this calculator

 d (coil diameter in inches)   (inches)   (mm)
 l (coil length in inches)  (inches)   (mm) 
 n (number of turns)    

 
  L (Inductance) (uH)  
  maximum wire diam (in) (mm)
Back to Calculations

If you want to get down to some serious inductance calculation go to
www.k7mem.150m.com/Electronic_Notebook/inductors/coildsgn.html

Page Last updated 08-04-2011