⚡ Inductive Reactance Calculator
Calculate inductive reactance from frequency and inductance
Example: 60 Hz (power line), 50 Hz (EU), 1000 Hz (audio)
Use millihenries (mH) or microhenries (μH) - convert to H (1 mH = 0.001 H)
How to Use This Calculator
Enter Frequency
Input the frequency of the AC signal in Hertz (Hz). For power line frequencies, use 60 Hz (North America) or 50 Hz (Europe/Asia). For audio or RF applications, use the appropriate frequency.
Enter Inductance
Input the inductance value in Henries (H). If your value is in millihenries (mH) or microhenries (μH), convert first: 1 mH = 0.001 H, 1 μH = 0.000001 H.
Calculate
Click the "Calculate Inductive Reactance" button to get the inductive reactance in Ohms (Ω). This represents the opposition to current flow in an inductor in an AC circuit.
Formula
XL = 2πfL
Where:
- XL = Inductive Reactance (Ohms, Ω)
- f = Frequency (Hertz, Hz)
- L = Inductance (Henries, H)
- π = Pi ≈ 3.14159
Example Calculation:
For an inductor of 10 mH (0.01 H) at 60 Hz:
XL = 2π × 60 × 0.01
XL = 3.77 Ω
Note: Inductive reactance increases with frequency - higher frequency means more opposition to current. At DC (f=0), reactance is zero (inductor acts like a short circuit after steady state).
About Inductive Reactance Calculator
The Inductive Reactance Calculator determines the opposition to alternating current (AC) flow in an inductor. Unlike resistance, reactance is frequency-dependent - higher frequencies result in greater reactance. Inductors block high-frequency signals while passing low-frequency signals, making them essential in filters, chokes, and tuning circuits.
When to Use This Calculator
- AC Circuit Analysis: Calculate impedance in AC circuits containing inductors
- Filter Design: Design high-pass and low-pass filters using inductors
- Power Electronics: Analyze inductor behavior in power supplies and converters
- Audio Engineering: Calculate reactance in audio crossover networks
- RF Engineering: Analyze inductor behavior in radio frequency circuits
Why Use Our Calculator?
- ✅ Quick Calculation: Instantly determine inductive reactance from frequency and inductance
- ✅ Frequency Dependent: Understand how reactance changes with frequency
- ✅ Circuit Design: Essential for AC circuit analysis and filter design
- ✅ Free Tool: No registration or payment required
- ✅ Educational: Learn about AC circuit behavior and inductor properties
Common Applications
Power Supply Filters: Calculate inductive reactance in power supply chokes that filter out AC ripple from DC power supplies. High reactance at the ripple frequency blocks AC while allowing DC to pass, making inductors ideal for smoothing power supply outputs.
Audio Crossovers: Design crossover networks in speakers where inductors create low-pass filters for woofers. The frequency-dependent reactance allows low frequencies to pass to the woofer while blocking higher frequencies, improving sound quality.
RF Tuning Circuits: Analyze inductor behavior in radio frequency tuning circuits, where inductive reactance combines with capacitive reactance to create resonant circuits for frequency selection in radios, filters, and oscillators.
Tips for Best Results
- Reactance is directly proportional to both frequency and inductance
- At DC (f=0), inductive reactance is zero - inductor acts like a short circuit
- Higher frequency means higher reactance - inductors block high frequencies
- Current lags voltage by 90° in a pure inductor
- For impedance: Z = √(R² + XL²) when resistance is present
Frequently Asked Questions
What is inductive reactance?
Inductive reactance (XL) is the opposition to alternating current flow in an inductor, measured in Ohms. Unlike resistance, reactance is frequency-dependent and increases linearly with frequency: XL = 2πfL. It represents how much an inductor resists changes in current.
How does reactance differ from resistance?
Resistance (R) opposes current in both DC and AC circuits and dissipates power as heat. Reactance (XL) only exists in AC circuits, doesn't dissipate power, and depends on frequency. Resistance and reactance combine as impedance: Z = √(R² + XL²).
Why does reactance increase with frequency?
Higher frequency means current changes more rapidly. Inductors oppose changes in current (Faraday's law), so faster changes create more opposition. At DC (zero frequency), there are no changes, so reactance is zero. At very high frequencies, reactance becomes very large, blocking current.
What is the phase relationship in an inductor?
In a pure inductor, current lags voltage by 90°. This means voltage peaks occur 90° before current peaks. This phase difference occurs because the inductor's back-EMF opposes current changes, causing current to lag behind the applied voltage.
How do I calculate total impedance with resistance?
If an inductor has both resistance (R) and reactance (XL), the total impedance is Z = √(R² + XL²), with a phase angle θ = arctan(XL/R). The current is I = V/Z, where V is voltage.
What happens at very high frequencies?
As frequency increases, inductive reactance increases without limit (XL → ∞ as f → ∞). This makes inductors ideal for blocking high-frequency noise and filtering. In practice, parasitic capacitance limits behavior at very high frequencies.