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 resistorView example
Capacitance (C)farads
Resistance (R)ohms
Time constantseconds
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
Fill in all values except the one you wish to calculate
  • Capacitance - Capacitance of the capacitor
  • Resistance - Resistance of the resistor
  • Time - Time constant of the circuit