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Reactance Calculator

Calculate inductive and capacitive reactance across a frequency and find where they balance.

About Reactance Calculator

Inductive reactance rises with frequency while capacitive reactance falls, so every LC pair has exactly one frequency where they cancel. Below it the circuit is capacitive, above it inductive. This crossover is what makes LC circuits frequency-selective and underlies every filter, tuner and oscillator.

Formula

Reactance

X_L = 2πfL; X_C = 1 ÷ (2πfC); they cancel at f = 1 ÷ (2π√(LC))

resonance
Frequency at which inductive and capacitive reactance are equal

Worked example

With the default values below, Reactance Calculator returns Inductive Reactance of 62.8319. Change any input above and every figure here is recalculated in your browser.

Inputs used

Inductanceminimum 0 H
0.01 H
Capacitanceminimum 0 F
0.000001 F
Frequencyminimum 0.01 Hz
1,000 Hz

Results

Inductive Reactance
62.8319 ohm
Capacitive Reactance
159.1549 ohm
Net Reactance
-96.3231 ohm
Frequency Where They Cancel
1,591.549 Hz
Dominant Behaviour
Capacitive — current leads voltage

Step by step

  1. 1Values used
  2. 2Reactance
  3. 3Inductive Reactance= 62.8319 ohm
  4. 4Capacitive Reactance= 159.1549 ohm
  5. 5Net Reactance= -96.3231 ohm
  6. 6Frequency Where They Cancel= 1,591.549 Hz
  7. 7Dominant Behaviour= Capacitive — current leads voltage

Assumptions and limits

  • The result is derived only from the 3 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 Reactance calculated?

X_L = 2πfL; X_C = 1 ÷ (2πfC); they cancel at f = 1 ÷ (2π√(LC)) Inductive reactance rises with frequency while capacitive reactance falls, so every LC pair has exactly one frequency where they cancel. Below it the circuit is capacitive, above it inductive.

Why does Reactance matter?

This crossover is what makes LC circuits frequency-selective and underlies every filter, tuner and oscillator.

What values do I need to enter?

This calculator takes 3 inputs: 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.

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Reactance Calculator – Calculate Inductive Reactance