# Capacitor Discharging (Online Calculator Free)

## The RC discharging circuit shows that five parameters are invloved in the discharging process; they are time t, Capacitance C, Resisitance R, the initial output voltage Vi, and the final output voltage Vf. If four of these parameters are known, then this online calculator can be used to calculate the fifth one.

Last Reviewed and Updated on February 7, 2020

An RC discharging circuit has a closed loop RC circuit with the resistance R in series with the capacitor C. Since the circuit is closed, the charge deposited on the capacitor will tend to even out, just like water evens out when a filled vessel is connected to an empty vessel with a pipe. This movement of the charge will cause the voltage across the capacitor to drop towards zero. The calculator in this page will help you calculate the voltage across the capacitor at any time t.

We shall follow the following circuit. This is a closed RC series circuit. The voltage across the capacitor changes from Vi to Vf in time t. The equation is: Vf = Vie-t/RC. This equation has been derived from the charging equation by putting Vcc = 0. ## Calculate t when R, C, Vf and Vi are known

Use this form to find the time taken by the voltage to reach Vf.

 R: kΩ C: μF Vi: V Vf: V t: milliseconds

## Calculate Vf when R, C, t and Vi are known

Use this form to find the value of Vf after a time t.

 R: kΩ C: μF Vi: V Vf: V t: milliseconds

## Calculate R when Vf, C, t and Vi are known

Use this form to find the value of R that will take the voltage to Vf after a time t.

 R: kΩ C: μF Vi: V Vf: V t: milliseconds

## Calculate C when Vf, R, t and Vi are known

Use this form to find the value of C that will take the voltage to Vf after a time t.

 R: kΩ C: μF Vi: V Vf: V t: milliseconds

## Capacitor Charging Calculator?

Click here for capacitor charging circuit calculator: Capacitor Charge and Discharge Online Calculator