Reference Designer Calculators



RC Time Constant Calculator


If a voltage is applied to a capacitor of Value C through a resistance of value R, the voltage across the capacitor rises slowly. The time constant is defined as the time it will take to charge to 63.21% of the final voltage value.



Following is the formula for time constant.

t = R * C

Enter two of the required values and Hit the third button to calculate the required value. You may also choose the suitable units.

  (Resistance) : None Kilo Ohm Mega Ohm
  (Capacitance) uF nF pF
  (Time Constant) seconds milli seconds micro seconds