Inductive Reactance Calculator
Calculate inductor reactance and current at a selected AC frequency
Inductive reactance
How we calculated it
About the Inductive Reactance Calculator
Inductive reactance describes the frequency-dependent opposition an ideal inductor presents to alternating current. It increases as frequency or inductance increases, the opposite trend from capacitive reactance.
The calculation is useful for coils, filters and AC networks, but real inductors also have winding resistance, core losses and parasitic capacitance.
How to Use the Inductive Reactance Calculator
- Enter inductance and its unit.
- Enter AC frequency.
- Calculate inductive reactance in ohms.
- Combine reactance with resistance and other impedance components when analyzing a full circuit.
How the Calculation Works
Inductive reactance XL = 2πfL, where f is frequency in hertz and L is inductance in henries.
Doubling frequency or inductance doubles the ideal reactance. At ideal DC frequency of zero, XL is zero although winding resistance can still remain.
Worked example
Inductive Reactance Calculator Worked Example
100 mH inductor at 60 Hz
L=0.1 H. XL = 2π×60×0.1 ≈ 37.70 Ω.
Result guide
Understanding Your Inductive Reactance Calculator Result
A larger inductive reactance means the inductor opposes AC current more strongly at that frequency. It does not include the coil’s ordinary resistive losses. In practical AC design, the same inductor can therefore behave almost like a short circuit at very low frequency and like a much stronger opposition at high frequency. That frequency dependence is why inductors are useful in chokes, filters and crossover networks rather than being treated as fixed resistors.
Before you rely on the answer
Assumptions and Limitations
- The inductor is modeled ideally for reactance.
- Frequency and inductance are finite non-negative values.
- Winding resistance and core losses are excluded.
Practical tip
Using This Result in Practice
If measured current differs significantly from a reactance-only prediction, include winding resistance and any other impedance in the analysis rather than assuming the formula is wrong.
Related calculations
Useful Calculations to Continue With
If the component is a capacitor, use the Capacitive Reactance Calculator.
If the inductor is paired with a capacitor, use the Resonant Frequency Calculator to find the ideal LC resonance.
Common questions
Inductive Reactance Calculator FAQ
Why does inductive reactance increase with frequency?
A faster-changing current creates a larger induced voltage that opposes the change.
What is inductive reactance at DC?
The ideal reactance is zero at zero frequency, although real winding resistance remains.
Is XL measured in ohms?
Yes, reactance is expressed in ohms.