kiloelectron volt

unit of measurement

Also known as: keV

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June 17, 2026

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A kiloelectron volt (keV) is a unit of energy commonly used in atomic and nuclear physics. It is equal to 1,000 electron volts (eV). An electron volt is the energy gained by an electron when it moves across an electrical potential difference of one volt.123

While the joule is the standard unit of energy for everyday objects, the electron volt is used for measurements on the atomic and subatomic scales. For instance, MeV (mega-electron volt) indicates 1 million electron volts, and GeV (giga-electron volt) indicates 1 billion electron volts.23

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particle accelerator
Accelerating particles
…above 10,000 eV, or 10 kiloelectron volts (keV). Many particle accelerators reach much higher energies, measured in megaelectron volts (MeV, or million eV), gigaelectron volts (GeV, or billion eV), or teraelectron volts (TeV, or trillion eV).
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…above 10,000 eV, or 10 kiloelectron volts (keV). Many particle accelerators reach much higher energies, measured in megaelectron volts (MeV, or million eV), gigaelectron volts (GeV, or billion eV), or teraelectron volts (TeV, or trillion eV).
Read More