RC / RL / RLC Circuit Calculator

RC, RL, and RLC Circuits – Definition

RC, RL, and RLC circuits are fundamental electrical systems consisting of combinations of resistors (R), capacitors (C), and inductors (L). These circuits determine how voltage and current behave over time—especially during switching, charging, discharging, and transient events. They are essential in filters, signal processing, power electronics, and control systems.

Background Theory

RC Circuit

An RC circuit stores and releases energy in the electric field of a capacitor. Its time constant is:

This constant defines how fast the capacitor charges or discharges.
Voltage equations:

RL Circuit

An RL circuit stores and releases energy in the magnetic field of an inductor. Its time constant is:

Current equations:

RLC Circuit

An RLC circuit is a second-order system capable of oscillation. Key parameters include:

Circuit behavior depends on damping:

• Underdamped: oscillatory response

• Critically damped: fastest non-oscillatory response

• Overdamped: slow non-oscillatory response

How This Calculator Works

This calculator provides quick analysis for all three circuit types:

RC Mode

• Computes time constant

• Displays charging and discharging equations

RL Mode

• Computes time constant

• Displays current rise and decay equations

RLC Mode

• Computes damping factor, natural frequency, resonant frequency, and damped frequency

• Classifies the system as underdamped, overdamped, or critically damped

By entering resistance (R), capacitance (C), and inductance (L), the calculator instantly displays the key transient and frequency-domain parameters required for engineering design, tuning, and circuit analysis.