EMC Laboratory 
4000 Enterprise Dr. 
Missouri University of Science
and Technology
Rolla, MO 65401
emclab@mst.edu

Inductance Calculations

Select the box with the geometry that you would like to calculate. The round-wire geometries are loops of wire with various shapes. The transmission line geometries are cross sections and the values calculated are the inductance per unit length.

In all cases, the current is assumed to flow in the outer surface of the conductors. The approximate formulas used to calculate the inductance are provided along with restrictions on the relative size of the various parameters. These formulas can be found in various texts and most of them are derived in the book "Inductance Calculations" by F. W. Grover.

Round-Wire Loop GeometriesTransmission Line Geometries

Square Loop

Twin Lead

Rectangular Loop

Round Wire over a Ground Plane

Circular Loop

Two Vertically Spaced Traces

Equilateral Triangle Loop

Wide Trace over Ground Plane

Isosceles Triangle Loop

Coplanar Traces