A passive filter (also known as a lumped element filter) is used to attenuate a signal above or below a determined frequency.
This passive filter calculator has you pick your composition (RC – Resistance/Capacitive, RL – Resistance/Inductance) and enter your values to calculate the cutoff/-3dB frequency.
The low-pass filter will pass a signal with minimal distortion up to the cutoff frequency, at which point it will block the input signal.
The high-pass filter will block the frequencies below the cutoff frequency and pass the ones above.
Enter two of three parameters; the calculator then calculates the third.
Example: Specify resistance and capacitance, the calculator calculates the 3 dB cut-off frequency (fG).