Energy units
Each unit in J
| Unit | Symbol | In J | |
|---|---|---|---|
| joule | J | 1 | exact |
| kilojoule | kJ | 1000 | exact |
| megajoule | MJ | 1 000 000 | exact |
| electronvolt | eV | 1.602 176 634 × 10−19 | exact |
| kiloelectronvolt | keV | 1.602 176 634 × 10−16 | exact |
| megaelectronvolt | MeV | 1.602 176 634 × 10−13 | exact |
| gigaelectronvolt | GeV | 1.602 176 634 × 10−10 | exact |
| hartree | Eₕ | 4.359 744 722 21 × 10−18 | CODATA 2022 |
| rydberg | Ry | 2.179 872 3611 × 10−18 | CODATA 2022 |
| erg | erg | 1 × 10−7 | exact |
| calorie (thermochemical) | cal | 4.184 | exact |
| calorie (International Table) | cal_IT | 4.1868 | exact |
| kilocalorie (food Calorie) | kcal | 4184 | exact |
| watt hour | Wh | 3600 | exact |
| kilowatt hour | kWh | 3 600 000 | exact |
| British thermal unit (IT) | Btu | 1055.055 852 62 | exact |
| foot pound-force | ft·lbf | 1.355 817 948 33 | exact |
Conversion matrix
1 unit of the row equals the cell value in the column unit.
| 1 … | J | kJ | MJ | eV | keV | MeV | GeV | Eₕ |
|---|---|---|---|---|---|---|---|---|
| J | 1 | 0.001 | 1 × 10−6 | 6.241 509 074 × 1018 | 6.241 509 074 × 1015 | 6.241 509 074 × 1012 | 6 241 509 074 | 2.293 712 278 × 1017 |
| kJ | 1000 | 1 | 0.001 | 6.241 509 074 × 1021 | 6.241 509 074 × 1018 | 6.241 509 074 × 1015 | 6.241 509 074 × 1012 | 2.293 712 278 × 1020 |
| MJ | 1 000 000 | 1000 | 1 | 6.241 509 074 × 1024 | 6.241 509 074 × 1021 | 6.241 509 074 × 1018 | 6.241 509 074 × 1015 | 2.293 712 278 × 1023 |
| eV | 1.602 176 634 × 10−19 | 1.602 176 634 × 10−22 | 1.602 176 634 × 10−25 | 1 | 0.001 | 1 × 10−6 | 1 × 10−9 | 0.036 749 322 18 |
| keV | 1.602 176 634 × 10−16 | 1.602 176 634 × 10−19 | 1.602 176 634 × 10−22 | 1000 | 1 | 0.001 | 1 × 10−6 | 36.749 322 18 |
| MeV | 1.602 176 634 × 10−13 | 1.602 176 634 × 10−16 | 1.602 176 634 × 10−19 | 1 000 000 | 1000 | 1 | 0.001 | 36 749.322 18 |
| GeV | 1.602 176 634 × 10−10 | 1.602 176 634 × 10−13 | 1.602 176 634 × 10−16 | 1 000 000 000 | 1 000 000 | 1000 | 1 | 36 749 322.18 |
| Eₕ | 4.359 744 722 × 10−18 | 4.359 744 722 × 10−21 | 4.359 744 722 × 10−24 | 27.211 386 25 | 0.027 211 386 25 | 2.721 138 625 × 10−5 | 2.721 138 625 × 10−8 | 1 |
Sources: SI Brochure (9th edition, 2019); NIST Special Publication 811 (2008), Appendix B; CODATA 2022 for the bohr, dalton, hartree and rydberg. Factors marked exact follow from the definitions of the units.