Capacitor Charge / Discharge Time Calculator
Calculate the RC time constant τ = R × C, charge or discharge time to a target voltage, and voltage values at 1τ, 2τ, 3τ, and 5τ.
Results
| Time Constant τ = RC | — |
| Time to Target Voltage t | — |
| Voltage at t = 1τ | — V |
| Voltage at t = 2τ | — V |
| Voltage at t = 3τ | — V (≈95% charged) |
| Voltage at t = 5τ | — V (≈99.3% charged) |
Formulas
Charge: V(t) = VS × (1 − e−t/τ)
Discharge: V(t) = V₀ × e−t/τ
τ = R × C