Calculate the cutoff frequency (-3dB) for passive low pass filters.
Filter Components
Cutoff Results
Enter parameters to calculate cutoff
About this calculator
Quick Reference
f_cCutoff frequency
RResistance
CCapacitance
LInductance
Overview
A low pass filter allows low-frequency signals to pass through while attenuating (weakening) higher frequencies. This is used in everything from cleaning up sensor data to getting deep bass out of speakers.
💡
Pro Tips
The cutoff frequency (f_c) is where the signal power is reduced to 50% (-3dB).
For an RC filter: f_c = 1 / (2 * π * R * C).
For an RL filter: f_c = R / (2 * π * L).
!
Fun Facts
"Wait, did you know that your ears are naturally low-pass filters? As humans get older, they lose the ability to hear high-frequency sounds, effectively 'filtering' their hearing."
"Most audio 'Woofers' use a low pass filter so they don't try to play high-frequency sounds that would sound terrible coming from a large cone."
"In digital photography, an 'anti-aliasing' filter is actually a high-quality physical low-pass filter placed on the camera sensor to prevent weird patterns in fine textures."
