Filter Frequency Calculator
RC filters are used everywhere — audio processing, instrumentation, analog sensors, microcontrollers, and power electronics.
This Filter Frequency Calculator instantly computes the cutoff frequency (fc) for both Low-Pass and High-Pass filters using the standard RC formula. Perfect for designers, students, technicians, and embedded engineers.
RC Low-Pass & High-Pass Cutoff Calculator
Select LPF or HPF.
Enter resistor value R (Ohms).
Enter capacitor value C (Farads).
Click Calculate Cutoff Frequency.
The tool displays the cutoff frequency using:
fc=1/(2πRC)
🧭 How to Use
FAQ
Q1. What is cutoff frequency?
A. The frequency at which the filter output falls to 70.7% (−3 dB) of the input signal.
Q2. Does this calculator work for both LPF and HPF?
A. Yes — both use the same RC cutoff formula.
Q3. What units should I use for capacitance?
A. Enter value in Farads (F). Example: 0.1 µF = 0.1 × 10⁻⁶ F.
Q4. Is this calculator suitable for audio filter design?
A. Absolutely — RC filters are commonly used in audio circuits.