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Electrical

RC Filter Cutoff Frequency Calculator

Find the −3 dB cutoff of a first-order RC filter.

Ideal component relationshipsUnits and assumptions explained below

Circuit parameters

Runs on your device

CIRCUIT RESULT

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter resistance, capacitance.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Cutoff frequency = 1/(2πRC).

A WORKED EXAMPLE

Using resistance = 100 Ω, capacitance = 0.0001 F, the result is 15.9154943 Hz. Change these example inputs to match your task; use the method above to check each step.

What to keep in mind

Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Common questions

Which inputs does this calculation need?

Find the −3 dB cutoff of a first-order RC filter. Enter resistance in Ω, capacitance in F. The filled example is editable and is not a saved personal record.

How should I interpret the result?

Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Methodology maintained by ClarityKit. How these tools are built and checked.