What is inductive reactance?

Inductive reactance (XL) is the opposition an inductor offers to alternating current. It increases with frequency: XL = 2πfL, where f is frequency in Hz and L is inductance in Henries. At DC (f=0), a pure inductor has zero reactance.

How do series inductors combine?

Series inductors simply add: L_total = L₁ + L₂ + ... (assuming no mutual coupling). The total reactance is XL = 2πf × L_total.

How do parallel inductors combine?

For two parallel inductors: 1/L_total = 1/L₁ + 1/L₂, or equivalently L_total = (L₁ × L₂)/(L₁ + L₂). Total reactance is lower than either individual inductor.

What is the Q factor of an inductor?

The quality factor Q = XL / R, where R is the series resistance. A high Q (>10) indicates a low-loss inductor. RF inductors have Q of 50–200; power inductors typically Q 10–50.

Inductor Reactance Calculator

Calculate inductive reactance XL = 2πfL for any inductance and frequency. Covers series/parallel inductors, Q factor, phase angle, energy stored, and self-resonant frequency.

Inductance Unit

Inductance ?

Frequency Unit

Frequency

Inductive Reactance XL

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Inductance (H) —

Frequency (Hz) —

Extended More scenarios, charts & detailed breakdown ▾

Inductance (mH)

Frequency (kHz)

Inductive Reactance XL (Ω)

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Professional Full parameters & maximum detail ▾

Inductance (mH)

Frequency (kHz)

Series Resistance R (Ω) ?

Peak Current I_peak (A)

Inductive Reactance XL (Ω)

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Phase Angle (°) —

Q Factor (XL/R) —

Self-Resonant Frequency (MHz) —

Energy Stored ½LI² (μJ) —

Time Constant τ = L/R (μs) —

How to Use This Calculator

Select the inductance unit (H, mH, or μH) and enter the inductance value.
Select the frequency unit and enter the frequency.
The simple tier gives XL instantly.
Use Extended tabs for series/parallel combinations.
Professional mode adds Q factor, phase angle, energy stored, and time constant.

Formula

XL = 2πfL (Ω)

Series: L_total = L₁ + L₂ | Parallel: 1/L_total = 1/L₁ + 1/L₂

Q = XL / R | Energy = ½LI² | τ = L/R

Example

L = 100 mH, f = 10 kHz: XL = 2π × 10,000 × 0.1 = 6,283 Ω. With R = 5 Ω, Q = 6283/5 = 1257.

Frequently Asked Questions

Inductive reactance (XL) is the opposition an inductor offers to alternating current. It increases with frequency: XL = 2πfL, where f is frequency in Hz and L is inductance in Henries. At DC (f=0), a pure inductor has zero reactance.
Series inductors simply add: L_total = L₁ + L₂ + ... (assuming no mutual coupling). The total reactance is XL = 2πf × L_total.
For two parallel inductors: 1/L_total = 1/L₁ + 1/L₂, or equivalently L_total = (L₁ × L₂)/(L₁ + L₂). Total reactance is lower than either individual inductor.
The quality factor Q = XL / R, where R is the series resistance. A high Q (>10) indicates a low-loss inductor. RF inductors have Q of 50–200; power inductors typically Q 10–50.

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Sources & References (5) ▾

HyperPhysics – Inductor Reactance — Georgia State University
OpenStax University Physics Vol. 2 Ch. 14 – Inductance — OpenStax
NIST Engineering Metrology Reference — NIST
Khan Academy – AC Circuits and Reactance — Khan Academy
Sedra & Smith – Microelectronic Circuits, 8th Ed. — Oxford University Press