Reactance Calculator
Calculate inductive or capacitive reactance from frequency and inductance/capacitance.
Assumptions used in this calculation
- Ideal component: Assumes an ideal inductor or capacitor with no parasitic resistance (ESR) or self-capacitance/inductance.
About this calculator
Unlike a resistor, an inductor or capacitor's opposition to AC current, its reactance, isn't a fixed number but depends on the signal's frequency, which means you can't reuse a reactance value calculated at one frequency for a circuit running at another, and getting this wrong throws off filter design, impedance matching, and resonance calculations. This calculator computes inductive reactance (Xl = 2πfL, which rises with frequency) for coils or capacitive reactance (Xc = 1 ÷ 2πfC, which falls with frequency) for capacitors, given the frequency and the component's inductance or capacitance. It's built for anyone designing AC filters, calculating the impedance of a component at a specific operating frequency, or working through crossover networks in audio electronics, letting you swap between the inductive and capacitive formulas without re-deriving them or converting units (mH, µF) by hand each time.
Worked example
10mH coil at 60Hz
Result: 3.77 Ω
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