Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Capacitance (F)

Filter capacitance.

Resistance (Ω)

Filter resistance.

Compute the first-order RC low-pass cutoff frequency fc = 1 / (2 * pi * R * C), where the output falls 3 dB. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

fc (Hz)

Frequency at which the response is down 3 dB.

• Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

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