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Electron-volts to Joules Conversion

Type an amount of energy in electron-volts and read the same energy expressed in joules. One electron-volt equals 0.0000000000000000001602176634 joules, so every conversion is one multiplication.

How to convert electron-volt energy into joules

The electron-volt (eV) and the joule (J) both measure energy, but they sit at very different scales. An electron-volt is such a small amount of energy that its joule equivalent is a decimal point followed by eighteen zeros before any significant digit appears.

Because of that, converting is a single step: take the figure in electron-volts and multiply it by 0.0000000000000000001602176634. The answer you get back is the energy in joules, and nothing else about the quantity changes.

Electron-volts to joules formula

E(J) = E(eV) x 0.0000000000000000001602176634

In words: the energy measured in joules equals the energy measured in electron-volts multiplied by 0.0000000000000000001602176634, which is the same constant written in scientific notation as 1.602176634 x 10^-19.

Worked example: 500 eV x 0.0000000000000000001602176634 = 0.0000000000000000801088317 J, about 8.010883 x 10^-17 J, the rounded figure shown in the reference table below.

Making sense of the results

Expect extremely small numbers. Each extra zero you add to the electron-volt value moves the joule figure one place closer to the decimal point, so the exponent only rises slowly: 1 eV lands at about 1.602177 x 10^-19 J, while 900 eV is still only about 1.441959 x 10^-16 J.

Going the other way is the same relationship in reverse. Since one electron-volt is 0.0000000000000000001602176634 joules, a figure in joules becomes electron-volts by dividing it by that constant.