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RC Time Constant Calculator

Calculate τ = RC and charge/discharge timing with tolerance analysis

±%
±%
Time Constant (τ)
1000.000 ms
Range: 940.500 ms to 1.060 s(±6.0%)
Cutoff Frequency (fc = 1/2πτ)
159.155 mHz
Range: 150.075 mHz to 169.224 mHz
RC CircuitVinRVoutCCharging CurvetV₀63%τ
Show formulas

Time Constant:

τ=R×C\tau = R \times C

Charging (capacitor voltage):

VC(t)=V0(1−e−t/τ)V_C(t) = V_0 \left(1 - e^{-t/\tau}\right)

Discharging (capacitor voltage):

VC(t)=V0⋅e−t/τV_C(t) = V_0 \cdot e^{-t/\tau}

Cutoff Frequency:

fc=12πτ=12πRCf_c = \frac{1}{2\pi\tau} = \frac{1}{2\pi RC}

τ = time constant (seconds)

R = resistance (ohms)

C = capacitance (farads)

V₀ = initial/final voltage

t = time (seconds)