# RC time constant calculator

## Calculates the time constant of a resistor-capacitor circuit. Time constant is the time required to charge or discharge the capacitor by ~63.2% of the difference between the initial and final value.

Example 1: Must calculate the time constant of a 47uF capacitor and 22 ohm resistor | View example |

You may use one of the following SI prefix after a value: p=pico, n=nano, u=micro, m=milli, k=kilo, M=mega, G=giga

Results |

Time constant | 1.034 milliseconds |

Rise time from 20% to 80% | 1.4476 milliseconds |

Rise time from 10% to 90% | 2.2748 milliseconds |

3dB cutoff frequency | ~153.921608 hertz |