Results
Enter R and C, then calculate.
How this works
Ideal capacitor; ignores ESR, leakage, and non-ideal switching. Use for order-of-magnitude timing and filter intuition.
RC time constant
Calculate the time constant from resistance and capacitance.
Ideal first-order RC time constant. Leakage, tolerances and input/output loading are not modelled.
Related calculators
Check the stated method and limits against your installation. Results are calculation aids, not certification.
Calculator guidanceNew calculator emails
Calculation model 2026-11-02.1