Convert Femtojoules to Electronvolts

Convert Femtojoules (fJ) to Electronvolts (eV) instantly and accurately.

Femtojoules (fJ)
Electronvolts (eV)

Conversion Formula

eV = fJ × 6241.509074

About Femtojoules

A femtojoule (fJ) is 10⁻¹⁵ J - the scale of gamma-ray photons, molecular motor work, and state-of-the-art digital logic. The electron rest-mass energy is 81.87 fJ; a 100 keV X-ray photon carries 16.02 fJ. A single myosin II motor protein power stroke dissipates ~5-40 fJ. ATP hydrolysis under cellular conditions yields ~80-100 fJ of free energy. Advanced 3 nm CMOS gates switch at ~0.1-1 fJ per operation. Ultrafast fiber laser oscillators produce pulses of 0.1-10 fJ before amplification. 1 fJ = 10⁻¹⁵ J = 6.242 keV.

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.

Quick Reference Table

Femtojoules (fJ)Electronvolts (eV)
1 fJ6241.51 eV
2 fJ12483 eV
5 fJ31207.5 eV
10 fJ62415.1 eV
25 fJ156038 eV
50 fJ312075 eV
100 fJ624151 eV

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