An electronvolt is the energy gained by an electron across one volt.
Electronvolts to Millijoules Converter — eV to mJ
Convert Electronvolt (eV) to Millijoule (mJ) using the exact conversion factor (1 electronvolt = 1.602177e-16 millijoule). See the formula, worked examples, conversion table, and common uses.
Electronvolts to Millijoules converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
Millijoule is 0.001 joule units.
Result = input x 1.60217663e-19 / 0.001.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Electronvolts to Millijoules
Electronvolt and Millijoule both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Electronvolt is most often used for particle physics (particle accelerator energies are often quoted in gev or tev).
Formula
millijoules = electronvolts × 1.602177e-16
This factor comes from each unit's defined relationship to the category's base unit: 1 electronvolt equals 1.602177e-19 base units, and 1 millijoule equals 0.001 base units, so dividing one by the other gives the direct electronvolt-to-millijoule factor of 1.602177e-16.
Simple example
1 eV × 1.602177e-16 = 1.602177e-16 mJ
1 electronvolt = 1.602177e-16 millijoules.
Real-world example
100 eV × 1.602177e-16 = 1.602177e-14 mJ
100 electronvolts = 1.602177e-14 millijoules.
Conversion table
| Electronvolt (eV) | Millijoule (mJ) |
|---|---|
| 1 eV | 1.602177e-16 mJ |
| 10 eV | 1.602177e-15 mJ |
| 50 eV | 8.010883e-15 mJ |
| 100 eV | 1.602177e-14 mJ |
| 500 eV | 8.010883e-14 mJ |
| 1,000 eV | 1.602177e-13 mJ |
Reverse conversion: Millijoule to Electronvolt
1.602177e-16 mJ × 6.241509e+15 = 1.000000228 eV
1.602177e-16 millijoules = 1.000000228 electronvolts.
electronvolts = millijoules × 6.241509e+15
For a page dedicated to this direction, see Millijoule to Electronvolt.
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
Understanding the Millijoule (mJ)
Millijoule is 0.001 joule units.
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.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millijoules are in 1 electronvolt?
1 electronvolt equals 1.602177e-16 millijoules, using the exact defined conversion factor rather than an estimate.
How do I convert electronvolt to millijoule?
Multiply the electronvolt value by 1.602177e-16. The converter above does this instantly to whatever precision you set.
How do I convert millijoule back to electronvolt?
Use the reverse factor: 1 millijoule equals 6.241509e+15 electronvolts. You can also use the swap control in the converter above to flip the direction instantly.
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.
What is a millijoule?
Millijoule (mJ) is a unit of engineering.
Is the electronvolt to millijoule 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.
Where is the electronvolt still used today?
Standard unit throughout particle physics, atomic physics, and chemistry worldwide
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.