Electronvolt to Joule Converter
Convert particle-scale energies from electronvolts (eV) to joules (J) with the exact CODATA 2018 factor of 1 eV = 1.602176634×10⁻¹⁹ J. Ideal for spectroscopy, accelerator design, semiconductor characterization, and any analysis that must report final results in SI units.
Educational use only. Experimental calibration, detector efficiency, and relativistic effects require domain-specific analysis.
Examples
- 1 eV ⇒ 1.602 × 10⁻¹⁹ J (energy of a 1.24 μm photon).
- 2.0 keV ⇒ 3.204 × 10⁻¹⁶ J, useful for X-ray spectroscopy calibration.
- 6.242×10¹⁸ eV ⇒ 1.000×10³ J, linking atomic-scale units to macroscopic kilojoules.
- 3.5 MeV ⇒ 5.607 × 10⁻¹³ J (typical alpha-particle emission).
FAQ
Is the eV to J factor exact?
Yes. The definition of the electronvolt is derived from the fixed elementary charge, so 1 eV = 1.602176634×10⁻¹⁹ J exactly.
Can I enter millielectronvolts or gigaelectronvolts?
Absolutely—use scientific notation (for example 2.5e-3 for meV or 7.0e9 for GeV) and the converter will scale the result automatically.
Why do researchers still quote eV instead of joules?
Electronvolts keep subatomic energies in a practical numeric range, but publishing in joules maintains SI compliance and allows easier comparison with macroscopic energy budgets.
Does temperature or medium change the conversion?
No. The conversion is purely mathematical; temperature or material only affects how you measure or interpret the energy, not the unit relationship.
Additional Information
- Conversion formula: Joules = Electronvolts × 1.602176634×10⁻¹⁹ (exact per CODATA 2018).
- Reverse conversion: divide joules by 1.602176634×10⁻¹⁹ to regain the original eV figure for lab notebooks.
- Publishing guidance: report final energies in joules to comply with ISO 80000-6 and SI Brochure recommendations.
- Need deeper context? Review [The Joule (J): SI Unit of Energy](/units-and-measures/the-joule-si-unit-of-energy/) and the [Electronvolt explainer](/units-and-measures/electronvolt-natural-energy-unit/) before submitting experimental data.