Reactance Calculator

Capacitive or inductive reactance at any frequency.

Reactance in one minute

Reactance is the frequency-dependent opposition of capacitors and inductors:

falls with frequency, while rises with it. At the frequency where the two are equal an LC pair resonates. Reactance shifts current and voltage by 90° rather than dissipating power — that's why bypass capacitors look like a short at high frequency while blocking DC.