In order to reduce the number of current detectors detecting phase current in a power converting device that controls a power converter connected to a motor, thereby achieving a size reduction, the power converting device includes a current detector that detects, of winding groups of multi-phase windings, a total value of values of current flowing into a first switching element connected to a first phase of a first winding group and a second switching element connected to a second phase of a second winding group, and calculates a current value of another phase from current detected by the current detector.