Online Calculator and Formulas to calculate the Capacitor charge and Discharge at a Specified Time

On this page you can calculate the discharge voltage of a capacitor in a RC circuit (low pass) at a specific point in time.

In addition to the values of the resistor and the capacitor, the original input voltage (charging voltage) and the time for the calculation must be specified

The result shows the charging voltage at the specified time and the time constant τ (tau) of the RC circuit. The capacitor is discharged approx. 99.33% after a period of 5 τ. This means that at specified times, well over 5 τ the charging voltage is close to zero.

\(\displaystyle U_C=U_0 · e^{-\frac{t}{τ}}\)

\(\displaystyle τ=R ·C\)

\(\displaystyle R\)

Resistor (Ω)

\(\displaystyle C\)

Capacitor (F)

\(\displaystyle τ\)

Time constant (sec)

\(\displaystyle U_0\)

Applied voltage (V)

\(\displaystyle U_C\)

Charging voltage at the capacitor (V)