Capacitor Impedance Calculator

A capacitor's opposition to alternating current — its impedance — changes with frequency, which matters when designing filters, audio circuits, or any AC system. Enter your capacitance (in pF, nF, µF, mF, or F) and frequency (in Hz, kHz, MHz, or GHz) into the Capacitor Impedance Calculator to get the Impedance Magnitude. Secondary outputs include Capacitive Reactance (Xc), Angular Frequency (ω), the real and imaginary parts of the impedance, and Phase Angle.

Results

Impedance Magnitude

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Capacitive Reactance (Xc)

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Angular Frequency (ω)

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Real Part

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Imaginary Part

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Phase Angle

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Frequently Asked Questions

What is capacitive reactance and how is it calculated?

Capacitive reactance (Xc) is the opposition that a capacitor offers to alternating current. It is calculated using the formula Xc = 1/(2πfC), where f is frequency and C is capacitance.

How does frequency affect capacitor impedance?

Capacitor impedance is inversely proportional to frequency. Higher frequencies result in lower impedance, while lower frequencies result in higher impedance, making capacitors act like frequency-dependent resistors.

What is the phase angle of a capacitor's impedance?

A pure capacitor has a phase angle of -90° (or -π/2 radians), meaning the current leads the voltage by 90 degrees in AC circuits.

What is the difference between impedance and reactance?

Reactance is the imaginary part of impedance that represents opposition to AC current. Impedance includes both resistance (real part) and reactance (imaginary part) in complex form.

How do I convert between different capacitance units?

Common conversions: 1 F = 1000 mF = 1,000,000 μF = 1,000,000,000 nF = 1,000,000,000,000 pF. The calculator automatically handles these conversions.

Why does a capacitor have complex impedance?

Capacitor impedance is complex because it introduces a phase shift between voltage and current. The real part is zero for an ideal capacitor, and the imaginary part represents the capacitive reactance.

What is angular frequency and how is it related to frequency?

Angular frequency (ω) is frequency expressed in radians per second, calculated as ω = 2πf. It's used in impedance calculations and represents how fast the AC signal oscillates.

Can I use this calculator for AC circuit analysis?

Yes, this calculator provides the complex impedance values needed for AC circuit analysis, including magnitude, phase angle, and both rectangular and polar forms.