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.

Applied voltage (V)

DC voltage applied across the capacitor.

Insulation resistance (MΩ)

Insulation resistance of the dielectric.

Estimate the leakage current of a capacitor from the applied voltage and its insulation resistance. 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]

Leakage current (µA)

Leakage current through the dielectric.

• 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.

• Ripple Rating Check

  Compare the ripple current applied to a capacitor against its rated ripple current and report the signed margin percent; negative values mean the rating is exceeded.

• Contactor Coil Current

  Calculate DC contactor-coil steady current from applied voltage and DC coil resistance; do not use this for AC inrush or inductive impedance.

• Dc Motor Armature Current

  Calculate DC motor armature current from applied voltage, back EMF, and winding resistance using the steady-state armature equation.