Calculate the -3dB cutoff frequency for RC and RL filters.
Input Parameters
Calculation Results
Enter parameters to calculate
About this calculator
Quick Reference
f꜀Cutoff Frequency (-3dB)
RResistance
CCapacitance
LInductance
Overview
The cutoff frequency (or corner frequency) is the boundary in a system's frequency response where the energy flowing through the system begins to be reduced rather than passing through. For filters, this is the -3dB point.
💡
Pro Tips
For RC filters: f꜀ = 1 / (2πRC).
For RL filters: f꜀ = R / (2πL).
Make sure units are in Ohms, Farads, and Henries.
!
Fun Facts
"At the cutoff frequency, the output power is half the input power."
"RC filters are used in almost every electronic device to smooth power supplies or remove noise."
"The phase shift at the cutoff frequency is exactly 45 degrees for a single-pole filter."
