RC Time Constant Calculator

Calculate RC circuit time constant, charge/discharge time, and voltage at any time for capacitor circuits.

Resistance in the RC circuit.
kΩ
Capacitance in the circuit.
μF
DC supply voltage.
V
Time at which to calculate voltage.
seconds

Results

Time Constant τ-seconds
Capacitor Voltage at t-V
Current at t-mA
Full Charge Time (5τ)-seconds
% Charged at t-%
References: Hayt — Circuit Analysis; NEC Table references