RC Time Constant Calculator – Resistance × Capacitance
Calculate an RC circuit time constant in seconds from resistance in ohms and capacitance in microfarads.
The RC time constant describes the characteristic charging or discharging timescale of a simple resistor-capacitor circuit. This implementation accepts resistance in ohms and capacitance in microfarads.
How it works
τ = R × C. Because the input capacitance is in µF, the calculator converts it to farads before returning τ in seconds.
Example
For R = 10,000 Ω and C = 100 µF, τ = 10,000 × 100×10⁻⁶ = 1 second.
How to use
- Enter resistance in ohms.
- Enter capacitance in microfarads.
- Calculate the RC time constant.
- Read the result in seconds.
Key features
- Ohm input
- Microfarad input with unit conversion
- Result in seconds
- Positive-value validation
Common uses
- Basic electronics calculations
- Timing-network examples
- Checking resistor-capacitor combinations
Frequently asked questions
Why is capacitance multiplied by 10⁻⁶?
The input is in microfarads; one microfarad equals 10⁻⁶ farads.
Does τ mean the capacitor is fully charged?
No. τ is a characteristic timescale; charging and discharging follow an exponential curve.
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