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Joules to Electron-Volts Conversion

Enter an amount of energy in joules and get the same energy stated in electron-volts. One joule is about 6.241509074×10^18 electron-volts, so a joule figure turns into a very large number of eV.

From joules to electron-volts

The joule and the electron-volt are both units of energy, so one can be restated in terms of the other by plain scaling. A joule is enormously larger than an electron-volt, which is why even a modest amount in joules expands into a huge count of eV.

The size of that step comes from the SI definition used throughout: one electron-volt is exactly 0.0000000000000000001602176634 joules, so one joule is 1 divided by that number, giving about 6.241509074×10^18 electron-volts.

Joule to electron-volt formula

E(eV) ≈ E(J) × 6.241509074×10^18. In words: multiply the energy in joules by about 6.241509074×10^18 and the outcome is the energy in electron-volts. The listed figures are worked from the unrounded factor, so a hand multiplication by the short form can land on a different last digit.

The same step as a division is E(eV) = E(J) ÷ 0.0000000000000000001602176634, and that is exactly how the result on this page is worked out.

Worked example: 2 J × 6.241509074×10^18 ≈ 1.248302×10^19 eV.

Using this converter

Type the energy in joules into the input field and press Convert; the figure shown beside the eV label is the equivalent energy in electron-volts.

Copy puts that figure on your clipboard and Clear empties the field, so a whole series of values can be run through one after another.