This paper deals with the problem of measuring reactive power in energy systems under nonsinusoidal conditions. The time-domain approach due to Fryze, which has now gained wide acceptance, is adopted for defining VAr under such conditions. A simple PC-based equipment for measuring reactive power is described. The system facilitates expeditious determination of all relevant variables involved, and the computation of the active and reactive components of current with respect to voltage. A simple, low cost hard ware circuit has been developed for generating the sampling frequency from the input voltage of arbitrary wave shape. The software used for carrying out the various mathematical operations is then presented. Results of measurements made on typical non-sinusoidal waveforms are given. The results are compared with those obtained from theoretical calculations.