Reactance Calculator

Calculate the inductive reactance or capacitive reactance of a component with the Reactance Calculator, and learn how with the integrated live example

The Reactance Calculator will calculate the inductive reactance and the capacitive reactance of a coil or capacitor, and display a live example of how to perform the calculation.

The formula for calculating the inductive reactance is:

$X_{L}=2\pi fL$

Where
X_L = Inductive reactance in ohms
f = Frequency in cycles per second or Hertz (Hz)
L = Inductance in Henrys

The formula for calculating the capacitive reactance is:

$X_{C}=\frac {1}{2\pi fC}$

Where
X_C = Capacitive reactance in ohms
f = Frequency in cycles per second or Hertz (Hz)
C = Capacitance in Farads

Example 1: Find the inductive reactance of a coil that has an inductance of 320 µH (0.00032 Henry) when the frequency is 3333 kc (3333000 cycles/sec)

$X_{L}=6.28\times 3333000\times 0.00032=6701.4\; ohms$

Example 2: Find the capacitive reactance of a coil that has a capacitance of 1300 pF (0.0000000013 Farad) when the frequency is 360 kc (360000 cycles/sec)

$X_{C}=\frac{1}{ 6.28\times 360000\times 0.0000000013}=340\; ohms$

Using the Reactance Calculator

Select whether to calculate the inductive reactance or the capacitive reactance

Frequency: You must enter a frequency for the calculator to work

Calculating inductive reactance: Enter the inductance

Calculating capacitive reactance: Enter the capacitance

How To Calculate Reactance: This feature displays a live example of how to calculate reactance using the figures that you enter

The result is calculated and updated automatically as you enter different numbers or change between the input fields. If the calculated result hasn’t updated after you’ve finished entering your values, click or tap on the result.

Reference: ARRL – The Radio Amateur’s Handbook