Hertz (Hz)

The hertz is the SI unit of frequency, one cycle per second.

Convert hertz to any frequency unit

1 hertz = 1 × 10-9 gigahertz

Quick facts

Unit
Hertz
Symbol
Hz
Measures
Frequency
System
Hertz
Definition
One cycle per second (s⁻¹).
Also written
cycles per second

1 hertz in other units

Gigahertz1 × 10-9 GHz
Megahertz0.000001 MHz
Kilohertz0.001 kHz
Revolutions per minute60 rpm
Beats per minute60 bpm
Terahertz1 × 10-12 THz
Cycles per second1 cps

What is a hertz?

The hertz is the SI unit of frequency, one cycle per second. It measures anything periodic: sound, electricity, radio waves, processor clocks and vibrations.

Where the hertz sits among frequency units

The hertz is number 13 of 24 on our scale of frequency units, ordered from smallest to largest.

Revolution per minute1 Hz = 60 rpm Beat per minute1 Hz = 60 bpm Hertzthis unit Cycle per second1 cps = 1 Hz Kilohertz1 kHz = 1,000 Hz Megahertz1 MHz = 1,000,000 Hz Gigahertz1 GHz = 1,000,000,000 Hz

What hertz are used for

  • Sound and music pitch
  • Mains electricity (50/60 Hz)
  • Screen refresh rates (60–240 Hz)
  • Vibration and mechanical engineering

Hertz in real life

  • Concert pitch A is 440 Hz
  • Mains power is 50 Hz in Europe and 60 Hz in North America
  • Gaming monitors refresh at 144 Hz or more

Top hertz conversions

Common amounts of hertz

Convert hertz to all 23 other units

Hertz

Cycles & rotation

Per unit of time

Convert to hertz

Frequently asked questions

What is a hertz?

The hertz is the SI unit of frequency, one cycle per second.

How is the hertz defined?

One cycle per second (s⁻¹).

How many gigahertz are in a hertz?

One hertz equals 1e-9 gigahertz.

How many megahertz are in a hertz?

One hertz equals 0.000001 megahertz.

How many kilohertz are in a hertz?

One hertz equals 0.001 kilohertz.