About this tool
Inductive & Capacitive Reactance Calculator is a free, in-browser tool for AC circuit analysis. Choose inductive or capacitive reactance, choose what to solve for — the reactance, the frequency, or the component value — and enter the other two quantities with convenient unit selectors (Hz/kHz/MHz, H/mH/µH, F/µF/nF/pF). All math runs locally; nothing is uploaded.
Inductive reactance is XL = 2πfL and capacitive reactance is XC = 1 ⁄ (2πfC), where f is frequency in hertz, L is inductance in henries and C is capacitance in farads. The calculator rearranges these to solve for whichever variable you pick — for example f = XL ⁄ (2πL) or C = 1 ⁄ (2πf·XC). The result is auto-prefixed (Ω, kΩ, kHz, µF and so on) so you never read a wall of zeros.
Use it to size a coupling capacitor, find a coil's opposition at a given frequency, or locate the frequency where a component reaches a target reactance. The tool also reports the angular frequency ω = 2πf for use in impedance and phase calculations.
Frequently asked questions
How do inductive and capacitive reactance differ?
Inductive reactance XL = 2πfL rises with frequency — a coil opposes high frequencies more. Capacitive reactance XC = 1 ⁄ (2πfC) falls with frequency — a capacitor opposes low frequencies more. Both are measured in ohms but their phase effects are opposite.
What is angular frequency ω?
Angular frequency ω = 2πf in radians per second is the form used inside the reactance formulas (XL = ωL, XC = 1 ⁄ ωC) and in impedance and phase math. The tool shows it alongside the result for convenience.
Which units can I mix?
Any combination. Enter frequency in Hz, kHz or MHz, inductance in H, mH or µH, and capacitance in F, µF, nF or pF; the tool converts everything to base SI units internally and auto-prefixes the answer to a readable scale.
Does this account for resistance?
No — reactance is the purely reactive opposition of an ideal inductor or capacitor. Total impedance combines reactance with resistance as Z = √(R² + X²); this tool computes the X term. Everything is calculated in your browser.
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