Convert joules, calories, kWh, BTU, eV and more.
| kcal | kJ |
|---|---|
| 1 | 4.184 |
| 5 | 20.92 |
| 10 | 41.84 |
| 25 | 104.6 |
| 50 | 209.2 |
| 100 | 418.4 |
| 1000 | 4,184 |
| kWh | MJ |
|---|---|
| 1 | 3.6 |
| 5 | 18 |
| 10 | 36 |
| 25 | 90 |
| 50 | 180 |
| 100 | 360 |
| 1000 | 3,600 |
| BTU | kJ |
|---|---|
| 1 | 1.0550559 |
| 5 | 5.2752793 |
| 10 | 10.550559 |
| 25 | 26.376396 |
| 50 | 52.752793 |
| 100 | 105.50559 |
| 1000 | 1,055.0559 |
| J | cal |
|---|---|
| 1 | 0.23900574 |
| 5 | 1.1950287 |
| 10 | 2.3900574 |
| 25 | 5.9751434 |
| 50 | 11.950287 |
| 100 | 23.900574 |
| 1000 | 239.00574 |
| Unit | Symbol | Equals |
|---|---|---|
| Joule | J | base unit |
| Kilojoule | kJ | 1 kJ = 1,000 J |
| Megajoule | MJ | 1 MJ = 1,000,000 J |
| Calorie (thermochemical) | cal | 1 cal = 4.184 J |
| Kilocalorie (food Calorie) | kcal | 1 kcal = 4,184 J |
| Watt-hour | Wh | 1 Wh = 3,600 J |
| Kilowatt-hour | kWh | 1 kWh = 3,600,000 J |
| British thermal unit (IT) | BTU | 1 BTU = 1,055.055853 J |
| Therm (US) | thm | 1 thm = 105,480,400 J |
| Foot-pound force | ft·lbf | 1 ft·lbf = 1.355817948 J |
| Electronvolt | eV | 1 eV = 1.602176634e-19 J |
| Erg | erg | 1 erg = 1e-7 J |
Convert energy and work between joules, calories, watt-hours, kilowatt-hours, BTU, foot-pounds, electronvolts and more. Handy for electricity bills, nutrition labels, heating and cooling, physics homework and engineering.
To relate energy to how fast it is used, see the power converter. For rotational effort, use the torque converter.
Convert kWh to MJ or BTU to compare tariffs, battery capacity and heating fuels.
Switch between kilocalories (food Calories) and kilojoules, the unit used on labels in many countries.
Work in joules, eV and ergs for atomic-scale and CGS calculations.
A "food Calorie" (Cal) is a kilocalorie: 1 kcal = 4,184 J. The small calorie (cal) is 4.184 J. Nutrition labels use kcal.
One kilowatt-hour is 3.6 million joules. It is the energy used by a 1 kW appliance running for one hour.
One kilowatt-hour equals exactly 3,600,000 joules (3.6 MJ).
Multiply kilocalories by 4.184 to get kilojoules. For example, 200 kcal is 836.8 kJ.
One kilowatt-hour is about 3,412.14 BTU (IT).
An electronvolt is the energy gained by an electron moving through 1 volt: exactly 1.602176634 × 10⁻¹⁹ joules. It is used in atomic and particle physics.