Electron Volt (eV) Converter
Convert energy between electron volts, joules, kiloelectron volts, megaelectron volts, and erg.
Type in any field — the others update instantly.
An electron volt (eV) is the amount of energy gained by a single electron when it accelerates through an electric potential difference of one volt.
Exact definition: 1 eV = 1.602176634 × 10⁻¹⁹ joules (exact, by definition since 2019)
This is an extremely tiny amount of energy in everyday terms — but it is perfectly suited to atomic and particle physics, where energies are naturally at this scale.
Unit hierarchy:
- 1 keV = 1,000 eV (kiloelectron volt)
- 1 MeV = 1,000,000 eV (megaelectron volt)
- 1 GeV = 1,000,000,000 eV = 10⁹ eV (gigaelectron volt)
- 1 TeV = 10¹² eV (teraelectron volt — LHC scale)
Converting to joules and ergs:
- 1 eV = 1.602176634 × 10⁻¹⁹ J
- 1 J = 6.241509 × 10¹⁸ eV
- 1 erg = 10⁻⁷ J = 6.241509 × 10¹¹ eV
Energy scale reference:
| Phenomenon | Energy |
|---|---|
| Visible light photons | 1.8 – 3.1 eV |
| UV photons | 3.1 – 124 eV |
| X-ray photons | 100 eV – 100 keV |
| Gamma rays | > 100 keV |
| Chemical bonds | 1 – 10 eV |
| Nuclear reactions | 1 – 10 MeV |
| LHC proton collisions | ~13 TeV |
| Thermal energy at room temperature | ~0.025 eV |
Applications: The electron volt is used throughout particle physics, atomic physics, nuclear physics, and photonics. When scientists say a particle accelerator reaches 13 TeV, they mean each proton carries 13 × 10¹² electron volts of energy — roughly the same kinetic energy as a flying mosquito, but packed into a single proton!