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RC Circuit Calculator

Science & Engineering

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.

kΩ
μF
V
s
V
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

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

Voltage at multiples of τ

TimeVoltageCharged %
1τ（1000.00 ms）3.161 V63.2%
2τ（2.000 s）4.323 V86.5%
3τ（3.000 s）4.751 V95.0%
4τ（4.000 s）4.908 V98.2%
5τ（5.000 s）4.966 V99.3% (full)

Common RC combinations

RCτfc
1 kΩ100 μF100.00 ms1.59 Hz
10 kΩ10 μF100.00 ms1.59 Hz
10 kΩ100 μF1.000 s0.16 Hz
10 kΩ470 μF4.700 s0.03 Hz
100 kΩ10 μF1.000 s0.16 Hz
100 kΩ100 μF10.000 s0.02 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

  1. Enter known quantities: fill values and confirm units in the RC Circuit Calculator.
  2. Instant solution: unknowns solve live with the formula shown transparently.
  3. Use constant/material tables: standard physical constants and material data are listed on this page.
  4. Compare conditions: change inputs to compare scenarios.

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

How do I use the RC Circuit Calculator?
Open the page and fill in the input fields — results update automatically. Time constant, charging curve.
Are the results accurate?
Yes. Standard formulas and conversion factors are used and verified.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
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Source & Updates

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

Last updated:

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

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