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RC / RL / RLC calculator — time constant, cutoff, resonance & phase

Lab-ready RC / RL / RLC calculator for time constants, two-element filters, and series resonance. It loads sample lab values per mode, logs every substitution, and exports CSV or shareable URLs for reports.

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What this calculator covers

The RC / RL / RLC calculator unifies four workflows used in electronics labs and classroom demonstrations. Every computation pushes a detailed step-by-step trail so you can follow the algebra from formula to substituted numbers.

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)

  1. Choose a mode (start with Time constant for quick RC/RL checks).
  2. Enter component values in Ω / F / H / Hz — scientific notation like 1e-6 is accepted.
  3. 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

All calculations stay in your browser. Scientific notation like 1e-6 works, and you can use Enter / Ctrl+S / Ctrl+L for quick actions.

Results

How it’s calculated

    FAQ

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

    Choose the time constant mode, enter R and C for RC (or R and L for RL), then run the calculator. It applies τ = RC or τ = L/R and derives the cutoff frequency fc = 1/(2π τ) for RC and fc = R/(2π L) for RL, with every step logged in the How it’s calculated list.

    What does the two-element filter analysis show?

    Select a network (RC or RL, low-pass or high-pass), provide component values and frequency, and the tool computes the divider magnitude, gain in dB, and phase angle from H(jω) while recording the impedance and angle steps.

    How is the series RLC resonance calculated?

    Enter R, L, and C in the RLC resonance mode. The calculator evaluates ω₀ = 1/√(LC), f₀ = ω₀/2π, Q = (1/R)√(L/C), damping ratio ζ = 1/(2Q), and bandwidth BW = f₀/Q while showing each substitution.

    How do I export or share results?

    Use Export CSV for a one-line snapshot of the current mode, inputs, and metrics. Copy URL preserves the same state (mode, R, C, L, f, options) so you can reopen or share the exact calculation.

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