RC filter cutoff frequency

The cutoff frequency of an RC low-pass filter is actually the frequency at which the amplitude of the input signal is reduced by 3 dB (this value was chosen because a 3 dB reduction in amplitude corresponds to a 50% reduction in power).

We can write the cutoff frequency equation for RC filter circuit as: f c = 1 / (2 * π * R * C ) .

This passive RC low pass filter calculator calculates the cutoff frequency point of the low pass filter, based on the values of the resistor, R, and the capacitor, C, of the circuit, according to the formula fc= 1/(2πRC) .