How to use this calculator
- Enter or choose inductance.
- Enter or choose inductance unit.
- Enter or choose frequency.
- Enter or choose frequency unit.
- The inductive reactance updates as you type. Use Copy result or Share to keep it.
Method
X_L = 2π × f × L = ω × L
- f
- frequency in Hz
- L
- inductance in henries
- ω
- angular frequency 2πf in rad/s
Worked example
- ω = 2π × 50 = 314.159 rad/s.
- X_L = 314.159 × 0.010 H = 3.1416 Ω.
A 10 mH inductor has a reactance of about 3.14 Ω at 50 Hz, rising to 3.77 Ω at 60 Hz.
What the result means
Reactance does not dissipate power; it shifts current 90° behind voltage. Combine it with resistance and any capacitance in the AC Impedance Calculator.
Assumptions and limits
- Ideal inductor with constant inductance and no winding resistance.
- At high frequency, self-capacitance makes real inductors resonate and stop behaving inductively.
- Iron-cored inductors change value with current.
Questions
How is reactance different from resistance?
Both are measured in ohms, but reactance stores and returns energy each cycle instead of turning it into heat.
What about capacitors?
Capacitive reactance falls with frequency: X_C = 1 ÷ (2πfC). The AC Impedance Calculator includes both.