RC time constant calculator

Enter your values. The answer and the full worked solution update as you type.

Result

Time constant τ470 ms
Capacitor voltage5.662 V
Charged47.18 %
Practically full (5τ)2350 ms

Step-by-step solution

Time constant

τ = R·C = 10 kΩ · 47 µF = 470 ms

Charging an empty capacitor

vC(t) = Vs·(1 − e−t/τ)
vC = 12·(1 − e−300/470) = 5.662 V

Key formulas

Time constant
τ = RC | τ = L/R
Response
x(t) = x(∞) + [x(0) − x(∞)]·e−t/τ
Capacitor at DC
open circuit; vC cannot jump
Inductor at DC
short circuit; iL cannot jump
Settled
t ≈ 5τ

Practise RC & RL transients

A calculator gives the answer. In the exam you need the method: practise it with new problems, hints and worked solutions.

</> Embed

Free for teachers and schools: paste this code into your course page, LMS or website. Students can use the calculator and its worked solution without an account.

More calculators