Kilojoules to Electronvolts Converter — kJ to eV

Convert Kilojoule (kJ) to Electronvolt (eV) using the exact conversion factor (1 kilojoule = 6.241509e+21 electronvolt). See the formula, worked examples, conversion table, and common uses.

Kilojoules to Electronvolts converter

Converter

Scientific Units Converter

Convert SI derived units, scientific notation-friendly units, atomic units, and lab measurements.

Result 1 kilojoule = 6.241509e+21 electronvolt
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From definition

Kilojoule is 1000 joule units.

To definition

An electronvolt is the energy gained by an electron across one volt.

Formula

Result = input x 1000 / 1.60217663e-19.

Energy units are compatible.

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About Converting Kilojoules to Electronvolts

Kilojoule and Electronvolt are both scientific-measurement units, spanning everything from atomic and laboratory scales to astronomical distances — the kind of conversion that comes up constantly in physics, chemistry, and astronomy when a result needs to move between conventions used in different subfields. Specifically: Kilojoule is 1000 joule units, and an electronvolt is the energy gained by an electron across one volt.

Formula

electronvolts = kilojoules × 6.241509e+21

This factor comes from each unit's defined relationship to the category's base unit: 1 kilojoule equals 1000 base units, and 1 electronvolt equals 1.602177e-19 base units, so dividing one by the other gives the direct kilojoule-to-electronvolt factor of 6.241509e+21.

Simple example

1 kJ × 6.241509e+21 = 6.241509e+21 eV

1 kilojoule = 6.241509e+21 electronvolts.

Real-world example

10 kJ × 6.241509e+21 = 6.241509e+22 eV

10 kilojoules = 6.241509e+22 electronvolts.

Conversion table

Kilojoule (kJ)Electronvolt (eV)
0.001 kJ6.241509e+18 eV
0.01 kJ6.241509e+19 eV
1 kJ6.241509e+21 eV
10 kJ6.241509e+22 eV
100 kJ6.241509e+23 eV
1,000 kJ6.241509e+24 eV

Reverse conversion: Electronvolt to Kilojoule

6.241509e+21 eV × 1.602177e-22 = 0.9999999881 kJ

6.241509e+21 electronvolts = 0.9999999881 kilojoules.

kilojoules = electronvolts × 1.602177e-22

For a page dedicated to this direction, see Electronvolt to Kilojoule.

Understanding the Kilojoule (kJ)

Kilojoule is 1000 joule units.

Understanding the Electronvolt

Electronvolt (eV) measures energy. The energy gained by a single electron accelerated through an electric potential difference of one volt — a very small amount of energy, exactly 1.602176634 × 10⁻¹⁹ joules. It is classified as a non-SI unit accepted for use with the SI, common in physics.

Where it's used: Standard unit throughout particle physics, atomic physics, and chemistry worldwide

Uses of the Electronvolt today

  • Particle physics (particle accelerator energies are often quoted in GeV or TeV)
  • Atomic and molecular energy levels
  • Semiconductor band-gap energies

Electronvolt — sources

  • BIPM SI Brochure, 9th edition — Electronvolt listed as a non-SI unit accepted for use with the SI, with its exact value fixed via the elementary charge.
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Frequently asked questions

How many electronvolts are in 1 kilojoule?

1 kilojoule equals 6.241509e+21 electronvolts, using the exact defined conversion factor rather than an estimate.

How do I convert kilojoule to electronvolt?

Multiply the kilojoule value by 6.241509e+21. The converter above does this instantly to whatever precision you set.

How do I convert electronvolt back to kilojoule?

Use the reverse factor: 1 electronvolt equals 1.602177e-22 kilojoules. You can also use the swap control in the converter above to flip the direction instantly.

What is a kilojoule?

Kilojoule (kJ) is a unit of scientific units.

What is a electronvolt?

Electronvolt (eV) measures energy. The energy gained by a single electron accelerated through an electric potential difference of one volt — a very small amount of energy, exactly 1.602176634 × 10⁻¹⁹ joules. It is classified as a non-SI unit accepted for use with the SI, common in physics.

Is the kilojoule to electronvolt conversion exact?

Yes. The energy gained by a single electron accelerated through an electric potential difference of one volt — a very small amount of energy, exactly 1.602176634 × 10⁻¹⁹ joules. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.

Why does this category span everything from atomic to astronomical scales?

Scientific work spans an enormous range of physical scales, from atomic distances (measured in angstroms or atomic mass units) to interstellar distances (measured in astronomical units or parsecs), so this category groups SI-derived and scale-specific units that researchers commonly need to convert between within their field.