Inductive Reactance Calculator

Inductive Reactance in AC Circuits

An inductor opposes changes in current. In alternating current circuits, that opposition appears as inductive reactance, measured in ohms. Reactance increases with both frequency and inductance.

Formula

$$X_L = 2\pi f L$$

Rearranged forms:

$$L = \frac{X_L}{2\pi f}, \quad f = \frac{X_L}{2\pi L}$$

Here $X_L$ is inductive reactance in ohms, $f$ is frequency in hertz, and $L$ is inductance in henries.

Practical Notes

At DC (0 Hz), an ideal inductor has zero reactance. At audio and RF frequencies, even small inductors can present significant opposition to current. Use this calculator to size inductors for filters, chokes, and impedance matching.

Frequently Asked Questions

What units should I use?

Enter frequency in hertz and inductance in henries. The result is inductive reactance in ohms.

How is reactance different from resistance?

Resistance dissipates energy as heat. Reactance stores and releases energy each cycle and depends on frequency.

What happens at 0 Hz?

Inductive reactance is zero at DC. An ideal inductor acts like a short circuit for steady current.

Can I solve for any one variable?

Yes. Given any two of $X_L$, $f$, and $L$, the third can be calculated from $X_L = 2\pi fL$.

Does this include wire resistance?

No. Real inductors also have a small series resistance. This tool models ideal inductive reactance only.

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Inductive Reactance Calculator

Inductive Reactance in AC Circuits

Formula

Practical Notes

Frequently Asked Questions

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