Compute inductive and capacitive reactance, series impedance, phase angle and resonant frequency.
Compute inductive and capacitive reactance, series impedance, phase angle and resonant frequency.
Series impedance |Z| (Ω)
How to use this tool
Signal frequency in hertz.
Inductance in millihenries, capacitance in microfarads.
Resistance in the same series branch, in ohms.
Positive phase means inductive (voltage leads current); negative means capacitive.
Formula & worked example
1 kHz, 10 mH, 1 µF, 50 Ω: XL = 62.83 Ω, XC = 159.15 Ω, |Z| = 108.53 Ω, phase −62.57° (capacitive), resonance 1,591.55 Hz.
Limitations — read this before you rely on it
This is ideal series RLC behaviour with frequency-independent components. Real inductors and capacitors have parasitic resistance, self-resonance and tolerance, so measured impedance deviates, especially at high frequencies.
Frequently asked questions
A capacitor passes changing current more easily at higher frequency, so its opposition drops as 1/f.
XL equals XC, they cancel, impedance equals resistance alone, and phase is zero.
No — for series RLC, |Z| is always at least R, with equality only at resonance.
The circuit is capacitive overall, so current leads voltage.
By convention inductive reactance is positive and capacitive negative in complex impedance; here both are shown as positive magnitudes.