Math
First-order RC Filter Calculator
Find a single-pole RC cutoff and ideal unloaded gain/phase at an entered frequency.
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How to use First-order RC Filter Calculator
Corner frequency is1/(2πRC). With x=2πfRC, low-pass magnitude is1/hypot(1,x); high-pass magnitude is x/hypot(1,x). Their phases follow the corresponding first-order transfer functions.
- Enter resistance (ohms), capacitance (f), frequency (hz).
- Choose the stated convention and check the units and supported model.
- Calculate, inspect the result, then copy or download it.
Good to know
- Positive ohms,farads,hertz. Ideal unloaded single-pole topology; no parasitics, op-amp bandwidth, stability or EMC validation.
- Runs locally. Text/JSON fields are capped at30,000 characters; stricter page-specific and numeric-string limits also apply. Numeric inputs are bounded to magnitude1e15 and nonzero magnitude at least1e-100 unless an exact-string mode states otherwise. Approximate summaries use12 significant digits; CSV numeric cells retain the complete stored value and potentially formula-like string cells gain a protective apostrophe; unsupported, non-finite or detected underflow states return an error.
Common questions
Is the corner gain zero or one?
Neither. At the ideal corner, both magnitudes are1/√2, about−3.0103dB under the amplitude-ratio convention.
Is the input uploaded or saved?
No. The tool calculates inside this browser tab and provides a local download; it does not persist your input.
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