RC Circuit Calculator

Enter resistance and capacitance to find the time constant, cutoff frequency, and charge/discharge behavior.

Resistance R (ohms)

Capacitance C (µF)

Supply Voltage (V) — optional, for voltage display

Time Constant τ = RC

seconds

Cutoff Frequency

—

At 1τ (63.2%)

—

At 2τ (86.5%)

—

At 5τ (99.3%)

—

RC Circuit Formulas

τ = R × C

f_c = 1 / (2πRC)

V_charge(t) = V₀(1 − e^(−t/τ))

V_discharge(t) = V₀ × e^(−t/τ)

RL time constant.

LC resonance.

Op-amp gain.

Turns ratio.

V=IR.

ADC bits.