RC Circuit Calculator

Time constant, charging curve

Quick Answer

RC Circuit Calculator: Time constant, charging curve. RC Circuit Calculator uses standard science & engineering formulas to compute accurate results instantly.

Resistor R

kΩ

Capacitor C

μF

Source voltage V₀

Time point t

Target voltage

Time constant τ

1000.00 ms

Cutoff fc = 0.16 Hz

V at t=0.5s1.967 V

% of V₀39.3%

Time to 3.16V999.67 ms

Cutoff fc0.16 Hz

Calculation steps

1τ = R×C = 10 kΩ × 100 μF = 1000.00 ms
2V(0.5s) = V₀(1−e^(−t/τ)) = 5(1−e^(−0.5/1.000)) = 1.967 V (39.3%)
3Time to reach 3.16 V: t = −τ·ln(1−V/V₀) = 999.67 ms
4Cutoff frequency fc = 1/(2πRC) = 0.16 Hz (as a filter)

Voltage at multiples of τ

Time	Voltage	Charged %
1τ（1000.00 ms）	3.161 V	63.2%
2τ（2.000 s）	4.323 V	86.5%
3τ（3.000 s）	4.751 V	95.0%
4τ（4.000 s）	4.908 V	98.2%
5τ（5.000 s）	4.966 V	99.3% (full)

Common RC combinations

R	C	τ	fc
1 kΩ	100 μF	100.00 ms	1.59 Hz
10 kΩ	10 μF	100.00 ms	1.59 Hz
10 kΩ	100 μF	1.000 s	0.16 Hz
10 kΩ	470 μF	4.700 s	0.03 Hz
100 kΩ	10 μF	1.000 s	0.16 Hz
100 kΩ	100 μF	10.000 s	0.02 Hz

At t=τ a charging cap reaches 63.2% of V₀; 5τ is conventionally "fully charged" (99.3%). RC circuits are everywhere: debounce circuits, camera flashes, power-on reset timing, and low-pass filters (signals above fc get attenuated 20dB/decade).

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How to Use

Enter known quantities: fill values and confirm units in the RC Circuit Calculator.
Instant solution: unknowns solve live with the formula shown transparently.
Use constant/material tables: standard physical constants and material data are listed on this page.
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Key Points

RC Circuit Calculator is a free online science & engineering tool — open and use, no sign-up.
All calculations run locally in your browser; your data never leaves the device.
Key capability: Time constant, charging curve.
Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

RC Circuit Calculator formula

RC Circuit Calculator uses standard science & engineering formulas to compute accurate results instantly.

FAQ

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Open the page and fill in the input fields — results update automatically. Time constant, charging curve.

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Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated: 2026-08-04

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Cite this page: YiJianSuan. RC Circuit Calculator[EB/OL]. https://www.yijiansuan.com/en/c/science/rc-circuit

Results provided by this tool are for reference only and do not constitute professional advice.

Voltage at multiples of τ

Common RC combinations

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How to Use

Key Points

Formula & How It Works

FAQ

Related Tools

Related Guides

Source & Updates

Voltage at multiples of τ

Common RC combinations