What is “hertz?”

Hertz is a measurement unit for vibrations or frequencies (certain amount of vibration in a certain period of time).

It is an international measure of frequency or vibration equal to 1 cycle per second.

The alternative current frequency used in North America is 60 hertz. An electromagnetic wave completes a full oscillation from its positive to its negative pole and back again in what is known as a cycle. For example, AC current cycles polarity 60 times per second, this might be called 60 Hz = 60 s -1 . A single Hertz is thus equal to one cycle per second.

In Europe and some other parts of the world it is 50 hertz.

Hz is short for Hertz and that’s the surname of one Heinrich Rudolf, the German physicist after whom the metric unit for measuring radio and electrical frequencies is named.

It measures electrical current, sound pitch, or the clock speed of a computer’s CPU.
The frequency range of human hearing is from 20Hz to 20kHz (20,000Hz).

Light waves vibrate at several trillion Hertz. 


The commonly used multiples are kilohertz (kHz, 1,000Hz), megahertz (MHz, 1,000,000), gigahertz (GHz, 1,000,000,000) and terahertz (THz, 1,000,000,000,000)