Joules (J) to Electronvolts (eV) Conversion

Joules

The joule (J) is the SI derived unit of energy, work, and heat, defined as the work done when a force of one newton displaces an object by one metre (J = N·m = kg·m²·s⁻²). Named after James Prescott Joule, who established the mechanical equivalent of heat in the 1840s, the joule unifies all forms of energy — mechanical, thermal, electrical, chemical, and nuclear — under one framework. One joule is small: lifting an apple (≈100 g) one metre requires about 1 joule, while a human at rest metabolises approximately 80 joules per second.

Electronvolts

The electronvolt (eV) is a unit of energy equal to exactly 1.602176634 × 10⁻¹⁹ joules, defined as the kinetic energy gained by a single electron accelerated through a potential difference of one volt. It is the standard unit in particle physics, atomic physics, and solid-state physics. Visible light photons carry 1.8–3.1 eV of energy; X-ray photons carry 100 eV to 100 keV; the proton beams at CERN's LHC reach 6.5 teraelectronvolts (TeV).

Convert Joules (J) to other units of Energy