Capacitive reactance calculator


The capacitive reactance calculator calculates the reactance for a capacitor at a specified frequency.

Parameters

The capacitive reactance calculator calculates the reactance for a capacitor from the following parameters:

  • Frequency (Hz):¬†Enter the frequency in Hertz.
  • Capacitance (F):¬†Enter the capacitance in in milifarad (mF), microfarad (uF), nanofarad (nF) or picofarad (pF).

What is capacitive reactance?

Capacitive reactance is the opposition to the flow of alternating current by the capacitance of an electrical circuit. It is measured in Ohms, but it is not exactly the same as electrical resistance, which is also measured in Ohms. Capacitive reactance affects both the amplitude and phase of an electrical current. Electrical resistance affects only the amplitude.

How is capacitive reactance calculated

The capacitive reactance \(X_{c}\) is calculated as:

\(X_{c}=\dfrac{ 1 } {2 \pi \cdot F \cdot C }\)

 

Example 1

Calculate the capacitive reactance of a 10uF capacitor at 100 kHz.

\(X_{c}=\dfrac{ 1 } {2 \pi \cdot 100 \times 10^3 \cdot 10 \times 10^{-6}}\)
\(X_{c}=0.1592\mskip3mu\Omega\)

Example 2

Calculate the capacitive reactance of a 5nF capacitor at 10 MHz.

\(X_{c}=\dfrac{ 1 } {2 \pi \cdot 10 \times 10^6 \cdot 5 \times 10^{-9}}\)
\(X_{c}=3.18\mskip3mu\Omega\)