The Hz is the unit of cycles per second and is short for Hertz named after the famous German scientist Heinrich Hertz.

If a body is rotating at 7 Hz this means it completes 7 cycles in one second. We often think of waves as having a particular rotational frequency expressed in Hz.

Related units are:

  • mHz – millihertz or 10-3 cycles per second
  • kHz – kilohertz or 103 cycles per second
  • MHz – megahertz or 106 cycles per second
  • GHz – gigahertz or 109 cycles per second
  • THz – terahertz or 1012 cycles per second

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