RC / RL / RLC Circuit Calculator
Calculate impedance, reactance, phase angle, and resonance frequency of circuits
Calculator
Enter resistance, capacitance, inductance, and frequency to analyze RC, RL, or RLC circuits. Select units as needed.
About the RC / RL / RLC Circuit Calculator
The RC / RL / RLC Circuit Calculator is a free online tool designed to analyze AC circuits containing resistors, capacitors, and inductors. It allows you to calculate key parameters such as impedance (Z), capacitive and inductive reactance (XC, XL), phase angle (θ), and resonant frequency (f₀) for series or parallel circuits. This calculator is useful for electrical engineers, students, and technicians working on circuit design and AC system analysis.
What You Can Calculate
- Capacitive Reactance (XC): Opposition to AC current due to capacitance, given by XC = 1 / (2πfC).
- Inductive Reactance (XL): Opposition to AC current due to inductance, calculated as XL = 2πfL.
- Impedance (Z): The total opposition to AC current, combining resistance and reactance, Z = √(R² + (XL − XC)²).
- Phase Angle (θ): The phase difference between voltage and current, found from θ = arctan((XL − XC) ÷ R).
- Resonant Frequency (f₀): The frequency at which inductive and capacitive reactances are equal, f₀ = 1 / (2π√(LC)).
These formulas describe how resistance (R), capacitance (C), inductance (L), and frequency (f) interact in AC circuits — forming the foundation of filter design, signal processing, and power electronics.
How to Use the Calculator
- Enter the circuit’s resistance (R), capacitance (C), inductance (L), and frequency (f).
- Select the correct units for each value (Ω, µF, mH, kHz, etc.).
- The calculator will automatically compute XL, XC, Z, θ, and f₀.
- Adjust values to explore how changes in frequency or components affect circuit behavior.
The results are displayed in ohms (Ω) for impedance and reactance, degrees (°) for phase angle, and hertz (Hz) for resonance frequency.
Applications of RC, RL, and RLC Circuits
RC, RL, and RLC circuits are essential in both analog electronics and power systems. They determine how circuits respond to AC signals and are used to control frequency response, phase shift, and transient behavior. Practical applications include:
- Filter design: Used to create low-pass, high-pass, band-pass, and band-stop filters.
- Oscillators and tuning circuits: Resonant LC networks are fundamental in radio frequency (RF) and audio circuits.
- Phase control and timing: RC and RL circuits are used in timing networks and signal conditioning.
- Power electronics: RLC analysis helps manage power factor and transient stability in AC systems.
By using this RC / RL / RLC Circuit Calculator, you can accurately model AC circuit behavior, predict resonance conditions, and optimize component values for efficient and stable operation.