Preferred RC Filter Designer
Find practical E12, E24, or E96 resistor and capacitor pairs for a target RC filter cutoff.
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Result
About this tool
Give a target cutoff and the page searches E12, E24 or E96 resistor and capacitor pairs that land near that frequency.
Use it when you know the cutoff you want and need values you can actually buy, instead of an exact R and C that nobody stocks.
The pair is chosen for the ideal 1/(2πRC) cutoff. Capacitor tolerance and the source or load impedance will move the real corner.
Example. A 1000 Hz low-pass target on the E24 series returns up to 10 resistor and capacitor pairs sorted by cutoff error against 1000 Hz.
Limit. Resistors are taken only from the chosen E12, E24, or E96 series inside the min and max resistance box, and capacitors come from a fixed list.