About Capacitor Reactance & RC Circuit Calculator
Calculate capacitive reactance (Xc = 1 / 2πfC), charging/discharging RC time constants (τ = RC), and electrostatic stored energy in Joules (E = 1/2 CV²). Includes 3-digit EIA ceramic capacitor code decoding.
Key Capabilities & Features
- Calculates capacitive reactance (Xc in Ω) across any AC frequency (Hz)
- Calculates RC circuit time constant τ (tau) for filter design and transient charging
- Computes stored electrical energy in Joules and millijoules (E = 1/2 C V²)
- Integrated 3-digit ceramic capacitor code decoder (e.g. 104 = 100 nF)
- Instant unit conversion between Microfarads (µF), Nanofarads (nF), and Picofarads (pF)
How to Use Capacitor Reactance & RC Circuit Calculator
Input Capacitance or EIA Code
Enter capacitance directly in µF or type a 3-digit ceramic code.
Set Operating Frequency & Voltage
Provide the signal frequency (Hz) and working DC voltage (V).
Review Impedance & Energy
Examine capacitive reactance in Ohms, RC tau charging time, and stored Joules.
Privacy & In-Browser Execution Guarantee
Client-side component physics engine runs 100% locally in your browser.
Frequently Asked Questions
What is capacitive reactance (Xc)?
Capacitive reactance is the opposition a capacitor offers to alternating current flow: Xc = 1 / (2π · f · C). As signal frequency increases, capacitive reactance drops toward zero.
What is one RC time constant (τ)?
One time constant τ = R · C represents the time required for a capacitor to charge to approximately 63.2% of its full supply voltage through a series resistor.