Capacitor Charge Time Calculator
Calculate how long it takes to charge a capacitor through a resistor.
Find the RC time constant and charge at any time.
Charge Time Results
Capacitor charging through a resistor follows an exponential curve.
Key formulas:
τ (time constant) = R × C
V(t) = V_supply × (1 - e^(-t/τ))
Where:
- τ (tau) = RC time constant in seconds
- R = resistance in Ohms
- C = capacitance in Farads
- V_supply = supply voltage
- t = time in seconds
Charge milestones:
| Time Constants | Charge Level |
|---|---|
| 1τ | 63.2% |
| 2τ | 86.5% |
| 3τ | 95.0% |
| 4τ | 98.2% |
| 5τ | 99.3% |
Practically full at 5τ (99.3% charged).
Example: R = 10 kΩ, C = 100 μF
- τ = 10,000 × 0.0001 = 1 second
- Full charge ≈ 5 seconds