Capacitive Reactance Calculator
Calculate capacitive reactance in AC circuits
About this calculator
The Capacitive Reactance Calculator determines the opposition a capacitor offers to alternating current (AC) in electrical circuits. Capacitive reactance, measured in ohms, varies inversely with frequency and capacitance - higher frequencies or larger capacitances result in lower reactance. This tool is essential for electrical engineers, students, and technicians designing AC circuits, filters, and power systems. Understanding capacitive reactance helps predict how capacitors will behave at different frequencies, enabling proper component selection and circuit optimization for various applications including motor starting circuits, power factor correction, and signal filtering systems.
How to use
Enter the capacitance value in farads (or use unit prefixes like μF, nF, pF) and the frequency in hertz. The calculator will instantly compute the capacitive reactance using the formula Xc = 1/(2πfC). Results are displayed in ohms, showing how much the capacitor opposes AC current flow at the specified frequency.
Frequently asked questions
What is capacitive reactance?
Capacitive reactance is the opposition a capacitor offers to alternating current, measured in ohms. Unlike resistance, it decreases as frequency increases.
How does frequency affect capacitive reactance?
Higher frequencies result in lower capacitive reactance. At very high frequencies, capacitors act almost like short circuits to AC signals.
What units are used for capacitive reactance?
Capacitive reactance is measured in ohms (Ω), the same unit used for electrical resistance, though the underlying physics differs significantly.