Capacitive Reactance Calculator
Calculate capacitive reactance and AC impedance for capacitors in alternating current circuits
Calculate Capacitive Reactance
Choose between linear frequency (Hz) or angular frequency (rad/s)
Capacitance of the capacitor
AC frequency of the signal
Capacitive Reactance Results
Formula used: Xc = 1 / (2π × f × C) = 1 / (ω × C)
Input values: C = 0.000e+0 F, f = 0.000 Hz
Impedance: Z = -jXc = -j0.00 Ω (complex form)
Reactance Analysis
Example Calculations
Audio Coupling Capacitor
Capacitance: 10 μF
Frequency: 1 kHz (audio signal)
Calculation: Xc = 1 / (2π × 1000 × 10×10⁻⁶) = 15.92 Ω
Application: Low impedance for audio frequencies
Power Line Filter
Capacitance: 100 nF
Frequency: 60 Hz (power line)
Calculation: Xc = 1 / (2π × 60 × 100×10⁻⁹) = 26.53 kΩ
Application: High impedance blocks low-frequency noise
Frequency Effects
f = 0 Hz
Xc = ∞
Open circuit (no current flow)
Low Frequency
High Xc
Blocks low frequencies
High Frequency
Low Xc
Passes high frequencies
f → ∞
Xc → 0
Short circuit at very high frequencies
Circuit Applications
AC Coupling
Blocks DC, passes AC signals
High-Pass Filter
Passes high frequencies, blocks low
Power Factor Correction
Compensates inductive loads
Timing Circuits
RC time constants
Understanding Capacitive Reactance
What is Capacitive Reactance?
Capacitive reactance (Xc) is the opposition that a capacitor offers to alternating current (AC). Unlike resistance, which opposes both AC and DC, reactance only affects AC signals. The reactance decreases as frequency increases, making capacitors frequency-dependent components.
Key Properties
- •Frequency dependent: Xc ∝ 1/f
- •Phase shift: Current leads voltage by 90°
- •No power loss: Reactive component only
- •Units: Ohms (Ω), same as resistance
Reactance Formulas
Xc = 1 / (2πfC)
Xc = 1 / (ωC)
Xc: Capacitive reactance (Ω)
f: Frequency (Hz)
ω: Angular frequency (rad/s)
C: Capacitance (F)
Complex Impedance
Pure capacitor: Z = -jXc
RC circuit: Z = R - jXc
Magnitude: |Z| = √(R² + Xc²)
Phase angle: φ = -arctan(Xc/R)
Applications: AC coupling, filtering, power factor correction, timing circuits, reactive power compensation