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Inductance of Parallel Wires

Calculator of total inductance of a pair of wires based on formulas from:
[1] Rosa, E.B. (1908). "The self and mutual inductances of linear conductors". Bulletin of the Bureau of Standards.
[2] H. A. Aebischer (2018). "Analytical Approximation for the Inductance of Circularly Cylindrical Two-Wire Transmission Lines with Proximity Effect" AEM Journal

Important: These equations apply only to an isolated pair of wires with currents in either the same or opposite directions (grounds or other wires far away). Relative permeability μr of conductors is assumed to be 1. The calculated inductance for currents in opposite direction: Lopposite = 2*Lsingle_self - 2*Lmutual (effective short on one end, same current magnitude).


Parallel wires diagram

Parallel wire inductance formula, same direction

Self inductance of a wire, in a parallel wire system

 Formula for mutual inductance of parallel wires

 skin depth        k value


Distance units: 


Wire Length, l  
Separation, d  
Diameter, 2r  
Conductivity, σ M S/m
Frequency, f MHz
Inductance, Lopposite nH
Inductance, Lsame nH