| Energy is generally expressed in joules (J).
The information in the table below provides a method of converting energy from other units to joules. |
| Scheme | multiply by |
| British thermal unit (Btu) | 1 055.056 |
| calorie (mean)(cal) | 4.190 02 |
| electronvolt (eV) | 0.000 000 000 000 000 000 160 217 7 |
| erg (erg) | 0.000 000 1 |
| foot poundal | 0.042 140 11 |
| foot pound-force(ft - lbf) | 1.355 818 |
| kilocalorie (mean)(kcal) | 4 190.02 |
| kilowatt hour(kW h) | 3 600 000 |
| quad | 1 055 056 000 000 000 000 | therm(EC) | 105 506 000 |
| therm (U.S.) | 105 480 400 |
| ton of TNT (equilvalent energy) | 4 184 000 000 |
| watt hour (W h) | 3 600 |
| watt second | 1 |