Electron Volt (eV) Converter
Convert energy between electron volts (eV), joules, keV, MeV, GeV, and erg.
Used in particle physics, photon energy calculations, and semiconductor band gaps.
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!