RC Circuit Calculator

Find the time constant of a resistor-capacitor circuit.

Time constant τ 0.1

Time to ~fully charge (5τ) 0.5

Formula: τ = R·C

Step-by-step with your numbers:

1. Values used:

2. Resistance = 1,000 Ω

3. Capacitance = 100 µF

5. Time constant τ = Capacitance / Resistance = 100 / 1,000 = 0.1

6. Time to ~fully charge (5τ) = 0.5

Did we solve your problem today?

The RC time constant sets how quickly a capacitor charges or discharges through a resistor.

The math behind it

τ = R·C. After one τ the capacitor reaches ~63%; after 5τ it is essentially fully charged.

1 kΩ, 100 µF → τ = 0.1 s, fully charged in ~0.5 s.

What happens after one time constant?

The capacitor reaches about 63.2% of the supply voltage.