MAXScanner electronics calculator
Updated 2026-09-16
RL Filter Calculator — Cutoff, Reactance & Time Constant
Calculate first-order RL cutoff frequency, inductive reactance, time constant and ideal low-pass/high-pass magnitude at a test frequency.
Inputs
Results
Cutoff 1,591.549 Hz
Reactance 62.83185 Ω
Gain 0.846733
Gain -1.44507 dB
Phase -32.14191°
τ 0.0001 s
More actions
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Your calculation, step by step
- 1.L = 10 mH = 0.01 H; Cutoff: fc = R ÷ (2πL) = 1,591.549 Hz.
- 2.XL = 2πfL = 2π × 1,000 × 0.01 = 62.83185 Ω.
Formula, example and limits
fc=R/(2πL); τ=L/R; XL=2πfL.
100 Ω with 10 mH gives fc ≈ 1.592 kHz.
- Ideal series RL network.
- Winding resistance and source/load impedance are excluded unless included in R.
Frequently asked questions
What sets RL cutoff?
Resistance and inductance set the corner through fc=R/(2πL).
Does inductor resistance matter?
Yes in real hardware; include relevant series resistance when appropriate.