RC Filter Frequency Response Calculator
Calculate first-order low-pass or high-pass amplitude, phase and corner frequency.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Evaluate the ideal series-RC transfer function at the entered sinusoidal frequency.
fc=1/(2πRC); Hlow=1/(1+jf/fc); Hhigh=jf/fc/(1+jf/fc)
Worked example
At the corner frequency either topology has amplitude1/√2 and gain≈−3.0103dB. Low-pass phase is−45° and high-pass phase+45°.
Assumptions and input details
Positive R and C, nonnegative signal frequency. Assume ideal components, a zero-impedance source and no output loading. Frequency-domain steady state differs from RC charging time and from RLC series impedance. At zero high-pass output, gain is zero, dB is negative infinity and phase is undefined. No component tolerance, parasitic effects, filter order selection or real-device bandwidth is inferred.
References: Texas Instruments: first-order filter transfer functions
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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