🎥 Filter Calculator

Calculate cutoff frequencies, component values, and visualize the frequency response of passive RC, RL, and LC filters.

RC Low-Pass Filter

fc = 1 / (2πRC)    -20 dB/decade rolloff

Solve for component given fc:

Gain (dB)
Phase (degrees)

RC High-Pass Filter

fc = 1 / (2πRC)    +20 dB/decade below fc

Solve for component given fc:

Gain (dB)
Phase (degrees)

RC Band-Pass Filter (Two-Stage)

flow = 1/(2πR1C1)    fhigh = 1/(2πR2C2)

A band-pass is formed by cascading a high-pass (sets lower cutoff) and a low-pass (sets upper cutoff).

Combined gain (dB)

LC Resonant Filter

fr = 1 / (2π√(LC))    Q = (1/R)√(L/C)
Ω
Impedance magnitude