How to Convert Kilojoules to Electronvolts (kJ to eV)
Energy conversions link food labels in kJ and kcal, SP Group bills in kWh and air-conditioner capacity in BTU. This guide shows how to convert kilojoules into electronvolts by hand, with examples and a quick-reference table.
The conversion
To convert kilojoules to electronvolts, multiply the value by 6.241509e+21. To go the other way, divide by the same number (or multiply by 1.602177e-22). For a quick estimate, multiply by about 6,200,000,000,000,000,000,000.
Electronvolts = kilojoules × 6.241509e+21
Worked examples
- 3 kJ = 1.872453e+22 eV
- 12.5 kJ = 7.801886e+22 eV
- 75 kJ = 4.681132e+23 eV
Kilojoules to Electronvolts table
| Kilojoules | Electronvolts |
|---|---|
| 1 kJ | 6.241509e+21 eV |
| 2 kJ | 1.248302e+22 eV |
| 5 kJ | 3.120755e+22 eV |
| 10 kJ | 6.241509e+22 eV |
| 20 kJ | 1.248302e+23 eV |
| 25 kJ | 1.560377e+23 eV |
| 50 kJ | 3.120755e+23 eV |
| 100 kJ | 6.241509e+23 eV |
| 250 kJ | 1.560377e+24 eV |
| 500 kJ | 3.120755e+24 eV |
| 1,000 kJ | 6.241509e+24 eV |
Common questions
Is kJ to eV exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Electronvolts to Kilojoules converter.
Mistakes to avoid
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Background
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
For any value, use the Kilojoules to Electronvolts Converter or browse all energy converters.
Run your own numbers: Kilojoules to Electronvolts Converter