A method and apparatus for estimating capacitor current in a feed-forward control system includes a circuit that conducts a current through an output capacitor to ground and estimates a current magnitude for the current in an output current estimator. The current estimator generates a voltage that corresponds to the estimated current magnitude by creating a voltage drop across an estimator circuit capacitor that equals a voltage drop across the output capacitor, by creating a voltage drop across an output of an RC network of the estimator circuit that equals or is proportional to a voltage drop across the output capacitor due to parasitic inductance and parasitic resistance of the output capacitor. The voltage drop across the output of the RC network of the estimator circuit is proportional to current flowing through the parasitic inductance and resistance of the output capacitor.