Convert Electronvolts to Joules
Convert Electronvolts (eV) to Joules (J) instantly and accurately.
Conversion Formula
J = eV × 1.602176634e-19
About Electronvolts
An electronvolt (eV) is the kinetic energy gained by one electron accelerated through 1 volt - exactly 1.602176634 × 10⁻¹⁹ J (fixed by the 2019 SI revision). It is the natural energy unit of atomic and particle physics: visible light photons carry 1.7-3.1 eV; hydrogen ionisation requires 13.6 eV; X-ray photons span 100 eV-100 keV; protons at the LHC reach 6.5 TeV. Rest masses use eV/c²: electron 0.511 MeV, proton 938.3 MeV, Higgs boson 125 GeV. Nuclear binding energy peaks at ~8 MeV/nucleon for iron-56. 1 eV = 1.602176634 × 10⁻¹⁹ J.
About Joules
The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.
Quick Reference Table
| Electronvolts (eV) | Joules (J) |
|---|---|
| 1 eV | 1.602 × 10-19 J |
| 2 eV | 3.204 × 10-19 J |
| 5 eV | 8.011 × 10-19 J |
| 10 eV | 1.602 × 10-18 J |
| 25 eV | 4.005 × 10-18 J |
| 50 eV | 8.011 × 10-18 J |
| 100 eV | 1.602 × 10-17 J |