RC Time Constant Calculator
Calculate the time constant from resistance and capacitance.
Ω
µF
Result
1 s
Time constant (τ): 1 second
Result in all units
Step-by-step solution
τ = R × C
What Is the RC Time Constant?
The RC time constant shows how quickly a resistor-capacitor circuit charges and discharges. It depends on the resistance and the capacitance.
How is it calculated?
How Is It Calculated?
τ = R × C
- Enter the resistance (ohms) and the capacitance (farads).
The capacitor is almost fully charged after about 5τ.
Frequently Asked Questions
What does the time constant tell us?
It is the time it takes for the capacitor to reach about 63% of its final value.