Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Capacitance (F)

Capacitance being charged.

Resistance (Ω)

Series charging resistance.

Supply voltage (V)

Charging supply voltage.

Time (s)

Elapsed charging time.

Compute the RC charging curve q(t) = C * V * (1 - e^(-t / (R * C))) for a capacitor charged through a resistor from a fixed supply. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Charge (C)

Charge stored on the capacitor at time t.

• Capacitance, ESR, leakage, ripple rating, lifetime, and self-resonance vary with frequency, temperature, DC bias, aging, dielectric, package, and mounting. Nominal capacitance alone does not determine in-circuit impedance or reliability.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• RC Charging Voltage

  Compute the charging voltage across an RC network after a given elapsed time.

• Capacitor Energy Calculator

  Compute the energy stored in a charged capacitor, E = 0.5 * C * V^2; doubling the charge voltage quadruples the stored energy.

• RC Time To Threshold

  Calculate RC charging time to a target voltage.