Inductive Reactance Calculator

Calculate the inductive reactance of an inductor from its inductance and AC frequency. Choose convenient frequency and inductance units and get the XL result instantly in ohms.

Calculate Inductive Reactance

Enter frequency and inductance to calculate XL = 2πfL.

Enter an AC frequency greater than zero.
Supports nH, µH, mH, H, and kH.
Inductive Reactance (XL)
0 Ω

What Is Inductive Reactance?

Inductive reactance is the opposition an inductor provides to alternating current. It is represented by XL and is measured in ohms (Ω).

Unlike ordinary resistance, inductive reactance depends on frequency. As the AC frequency increases, an inductor provides greater opposition to changes in current.

Inductive Reactance Formula

Inductive reactance can be calculated from the AC frequency and the inductance of the component.

XL = 2πfL

In this formula, XL represents inductive reactance in ohms, f is frequency in hertz, L is inductance in henries, and π is approximately 3.14159.

How to Use the Inductive Reactance Calculator

  1. Enter the frequency of the AC signal.
  2. Select Hz, kHz, MHz, or GHz.
  3. Enter the inductance of the component.
  4. Select nH, µH, mH, H, or kH.
  5. Click Calculate Reactance.
  6. The equivalent XL value will appear in a suitable ohm unit.

The calculator automatically converts all selected inputs to hertz and henries before applying the inductive reactance formula.

Inductive Reactance Calculation Example

Consider a 10 mH inductor operating at an AC frequency of 1 kHz. First convert the two quantities to SI units.

f = 1 kHz = 1,000 Hz
L = 10 mH = 0.01 H

XL = 2 × π × 1000 × 0.01

XL ≈ 62.83 Ω

The inductor therefore provides approximately 62.83 ohms of inductive reactance at 1 kHz.

How Frequency Affects Inductive Reactance

Higher Frequency

Increasing frequency increases inductive reactance. An inductor therefore opposes higher-frequency AC signals more strongly.

Lower Frequency

Lower frequency produces less inductive reactance, assuming the inductance remains unchanged.

Ideal DC

At zero frequency, the ideal inductive reactance calculated from XL = 2πfL is zero. Real inductors still have winding resistance and other non-ideal effects.

How Inductance Affects Reactance

Inductive reactance has a direct relationship with inductance. If frequency remains constant, increasing inductance increases the reactance by the same proportion.

For example, doubling the inductance doubles XL at the same frequency. This makes inductance an important design parameter in filters, chokes, transformers, oscillators, and other frequency-dependent circuits.

Frequency and Inductance Units

Quantity Unit Base Conversion
Frequency Hz 1 Hz
Frequency kHz 1,000 Hz
Frequency MHz 1,000,000 Hz
Frequency GHz 1,000,000,000 Hz
Inductance nH 10-9 H
Inductance µH 10-6 H
Inductance mH 10-3 H
Inductance H 1 H

Inductive vs Capacitive Reactance

Inductive Reactance

XL increases as frequency increases. The formula is XL = 2πfL.

Capacitive Reactance

XC decreases as frequency increases. Its formula is XC = 1 / (2πfC).

Opposite Behavior

Inductors and capacitors respond oppositely to changes in frequency, which makes them useful together in AC filters and resonant circuits.

Where Is Inductive Reactance Used?

Filters

Inductive reactance helps determine how inductors block or pass different frequency ranges in filtering circuits.

Power Systems

Inductive loads such as motors and transformers introduce reactive effects that are important in AC power analysis.

RF Circuits

Reactance calculations are used when selecting inductors for radio-frequency matching, tuning, oscillators, and resonant networks.

Frequently Asked Questions

What is inductive reactance?

Inductive reactance is the opposition an ideal inductor presents to alternating current. It is measured in ohms and depends on both frequency and inductance.

What is the formula for inductive reactance?

The formula is XL = 2πfL, where f is frequency in hertz and L is inductance in henries.

Does inductive reactance increase with frequency?

Yes. Inductive reactance is directly proportional to frequency, so a higher frequency results in a larger XL.

What happens when inductance increases?

Increasing inductance increases the inductive reactance when the frequency remains constant.

What is the unit of inductive reactance?

Inductive reactance is measured in ohms (Ω), with larger values commonly displayed in kilo-ohms or mega-ohms.

Can I enter millihenries and kilohertz directly?

Yes. The calculator automatically converts mH to henries and kHz to hertz before performing the calculation.