RF Round Wire Inductance Calculator


Calculator input form

Conductivity (ρ): S/m
Conductor relative permeability (μr):
Conductor diameter (d): mm
Frequency: MHz

No symbols in output:

New results window for each calc:

Long output:



This calculator computes the inductance and resistance of a round straight wire.

Adjustments are made for conductor internal impedance in accordance with David Knight's Rac-TED-ML and Li-ACA-3.05 to improve accuracy in the transition region.


The calculator involves this page, and a results page which is written in php and include some java scripting..



The calculator works with precision greater than the probable accuracy of the model or the source data. The results can be no better than the accuracy of the source data.

The calculator derives an RLGC model from the supplied data, and all calculated values are derived consistently from that RLGC model.

The accuracy of the modelling technique depends on compliance with the stated assumptions and the accuracy of the specified data.

Transmission line manufacturing tolerances are the most likely cause of the greatest error for new transmission lines, and for those that have been in service, degradation (eg ingress of water, contamination of dielectric, physical distortion, stretching, crushing etc) is a potential further source of significant error.

Results window

Results are returned in a separate window. Each instance of the calculator uses its own output window, so different scenarios can be explored in separate browser instances of the calculator and they will return results in separate results windows. The "New results window for each calc" switch on the calculator form will force new results into a new results window. If the calculator window is refreshed, results will be written to a new results window.

V1.01. Use at your own risk, not warranted for any purpose. Do not depend on any results without independent verification.  


© Copyright: Owen Duffy 1995, 2021. All rights reserved. Disclaimer.