How To Calculate R And C Of Low Pass Filter

Low pass filters are essential in electronics, and calculating the resistor (R) and capacitor (C) values is crucial for their design. This calculator simplifies that process.

1. Enter the desired cutoff frequency in Hertz.
2. Select the filter order.
3. Click ‘Calculate’.

The formula for calculating R and C in a low pass filter is:

R = 1 / (2 * π * fc * Q)

C = 1 / (2 * π * fc * R)

Where fc is the cutoff frequency, and Q is the quality factor, which depends on the filter order.

Comparison of R & C values for different filter orders

Filter Order	R (Ω)	C (F)

• Always use high-quality components for accurate results.
• Consider the tolerance of your components when calculating.
• Use a chart or graph to visualize your filter’s response.

What is the cutoff frequency?

The cutoff frequency is the point at which the filter begins to attenuate signals.

Learn more about low pass filters

Understand filter theory