A kilowatt-hour is 3.6 million joules.
kWhs to Kilojoules Converter — kWh to kJ
Convert kWh (kWh) to Kilojoule (kJ) using the exact conversion factor (1 kwh = 3,600 kilojoule). See the formula, worked examples, conversion table, history, and common uses.
kWhs to Kilojoules converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
Kilojoule is 1000 joule units.
Result = input x 3.6e+6 / 1000.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting kWhs to Kilojoules
kWh and Kilojoule both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). kWh is most often used for residential and commercial electricity billing worldwide.
Formula
kilojoules = kwhs × 3600
This factor comes from each unit's defined relationship to the category's base unit: 1 kwh equals 3600000 base units, and 1 kilojoule equals 1000 base units, so dividing one by the other gives the direct kwh-to-kilojoule factor of 3600.
Simple example
1 kWh × 3600 = 3,600 kJ
1 kwh = 3,600 kilojoules.
Real-world example
100 kWh × 3600 = 360,000 kJ
100 kwhs = 360,000 kilojoules.
Conversion table
| kWh (kWh) | Kilojoule (kJ) |
|---|---|
| 1 kWh | 3,600 kJ |
| 10 kWh | 36,000 kJ |
| 100 kWh | 360,000 kJ |
| 500 kWh | 1,800,000 kJ |
| 1,000 kWh | 3,600,000 kJ |
| 2,000 kWh | 7,200,000 kJ |
Reverse conversion: Kilojoule to kWh
1 kJ × 0.0002777777778 = 0.0002777778 kWh
1 kilojoule = 0.0002777778 kwhs.
kwhs = kilojoules × 0.000277777777778
For a page dedicated to this direction, see Kilojoule to kWh.
Understanding the kWh
kWh (kWh) measures energy. A kilowatt-hour is the energy of one kilowatt of power sustained for one hour: exactly 3,600,000 joules. It is classified as a Non-SI unit accepted for use with SI.
Where it's used: Used worldwide for electricity billing
Uses of the kWh today
- Residential and commercial electricity billing worldwide
- Battery capacity ratings (especially electric vehicles)
- Energy policy and grid-scale power statistics
History of the kWh
The kilowatt-hour became the standard electricity billing unit as power utilities expanded in the late 19th and early 20th centuries, since it conveniently matches the scale of typical household electricity consumption, unlike the much smaller joule.
Historical origin. kWh was not the invention of a single named person; it developed through the process described above.
Understanding the Kilojoule (kJ)
Kilojoule is 1000 joule units.
kWh — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the kilowatt-hour among accepted non-SI energy units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many kilojoules are in 1 kwh?
1 kwh equals 3,600 kilojoules, using the exact defined conversion factor rather than an estimate.
How do I convert kwh to kilojoule?
Multiply the kwh value by 3600. The converter above does this instantly to whatever precision you set.
How do I convert kilojoule back to kwh?
Use the reverse factor: 1 kilojoule equals 0.0002777778 kwhs. You can also use the swap control in the converter above to flip the direction instantly.
What is a kwh?
kWh (kWh) measures energy. A kilowatt-hour is the energy of one kilowatt of power sustained for one hour: exactly 3,600,000 joules. It is classified as a Non-SI unit accepted for use with SI.
What is a kilojoule?
Kilojoule (kJ) is a unit of energy.
Is the kwh to kilojoule conversion exact?
Yes. A kilowatt-hour is the energy of one kilowatt of power sustained for one hour: exactly 3,600,000 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 kwh still used today?
Used worldwide for electricity billing