A

David

Darling

hertz (Hz)

The hertz (Hz) is the derived unit of frequency in the SI system of units. One hertz is a frequency of one cycle per second. 1000 Hz = 1 kilohertz (kHz); 1000 000 Hz = 1 megahertz (MHz). The unit is named after the German physicist Heinrich Hertz who demonstrated the existence of radio waves in 1886.