Impedance Calculator
Calculate the total impedance of a series RLC combination and its phase angle.
About Impedance Calculator
Inductive and capacitive reactance oppose each other, so they subtract before being combined with resistance in quadrature. Where they cancel exactly, impedance falls to the resistance alone — series resonance. The sign of the phase angle tells you whether the circuit is inductive or capacitive, which determines how it behaves in a power system.
Formula
Impedance
Z = √(R² + (X_L − X_C)²); X_L = 2πfL, X_C = 1 ÷ (2πfC)
- X_L
- Inductive reactance, rising with frequency
- X_C
- Capacitive reactance, falling with frequency
Worked example
With the default values below, Impedance Calculator returns Total Impedance of 318.6972. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Resistanceminimum 0 ohm
- 100 ohm
- Inductanceminimum 0 H
- 0.05 H
- Capacitanceminimum 0 F
- 0.00001 F
- Frequencyminimum 0.01 Hz
- 50 Hz
Results
- Total Impedance
- 318.6972 ohm
- Inductive Reactance
- 15.7080 ohm
- Capacitive Reactance
- 318.3099 ohm
- Net Reactance
- -302.6019 ohm
- Phase Angle
- -71.713 degrees
Step by step
- 1Values used
- 2Impedance
- 3Total Impedance= 318.6972 ohm
- 4Inductive Reactance= 15.7080 ohm
- 5Capacitive Reactance= 318.3099 ohm
- 6Net Reactance= -302.6019 ohm
- 7Phase Angle= -71.713 degrees
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Impedance calculated?
Z = √(R² + (X_L − X_C)²); X_L = 2πfL, X_C = 1 ÷ (2πfC) Inductive and capacitive reactance oppose each other, so they subtract before being combined with resistance in quadrature. Where they cancel exactly, impedance falls to the resistance alone — series resonance.
Why does Impedance matter?
The sign of the phase angle tells you whether the circuit is inductive or capacitive, which determines how it behaves in a power system.
What values do I need to enter?
This calculator takes 4 inputs: Resistance, Inductance, Capacitance, Frequency. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.