RC / RL / RLC Calculator — time constant, cutoff

What this calculator covers

This RC / RL / RLC calculator unifies four workflows used in electronics labs and classes. Each run records a clear step trail from formula to substituted numbers.

Compute RC and RL time constants, including the associated cutoff frequency in Hz.
Analyse two-element divider networks to obtain magnitude |H|, gain in dB, and phase shift.
Inspect series RLC resonance, reporting ω₀, f₀, quality factor Q, damping ratio ζ, and bandwidth.
Combine any two resistors, capacitors, or inductors in series or parallel to get the equivalent value.

Step-by-step logging Each calculation writes the exact substitutions used so students can verify every transformation.

Share or export Persist inputs in the URL, copy links, and export CSV snapshots for lab notes.

Keyboard ready Press Enter to run, Ctrl+S for CSV, and Ctrl+L to copy the shareable URL.

How to use (3 steps)

Choose a mode (start with Time constant for quick RC/RL checks).
Enter component values in Ω / F / H / Hz — scientific notation like 1e-6 is accepted.
Run to see the results and steps, then tweak values or copy the URL / CSV.

Mode switches preload realistic lab defaults and auto-run so you immediately see a worked example.

Inputs

Results

How it’s calculated

FAQ

How do I compute RC and RL time constants and cutoff frequency?

Choose Time constant mode, enter R and C for RC or R and L for RL, then run. The tool applies τ = RC or τ = L/R and derives cutoff frequency. Every substitution appears in How it’s calculated.

What does the two-element filter analysis show?

Select RC or RL low-pass/high-pass, then enter values and frequency. The tool reports divider magnitude, gain in dB, and phase angle from H(jω), with impedance steps.

How is the series RLC resonance calculated?

Enter R, L, and C in RLC mode. The calculator evaluates ω₀, f₀, Q, damping ratio ζ, and bandwidth BW, then shows each substitution step.

How do I export or share results?

Use Export CSV for a one-line snapshot of current mode and inputs. Copy URL keeps the same state, so you can reopen or share the exact calculation.

How should I interpret Q and bandwidth in RLC mode?

Q describes how sharp the resonance is. A larger Q means a narrower bandwidth around resonance, while a smaller Q means broader response and heavier damping.

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