Abstract: This disclosure relates to a wide range frequency counter which functions as a highly accurate four range portable frequency counter. Accurate timing intervals of the frequency counter are obtained from a crystal controlled clock oscillator preferably operating at 5.24288 Mhz installed in a temperature controlled oven operating preferably at 65 degrees C. A seven figure LED digital display is used as the visual readout. The first "on" position of a range selector switch consists of a basic 5 Mhz counter which can count from less than 20 hertz to 5 Mhz. The basic counter is used with several combinations of integrated circuit (IC) prescalers to provide three other full-scale counting ranges. The frequency counter uses rechargeable batteries and has current-saving features to allow a useful operation period of six hours in the portable internally powered mode.