The kilowatt-hour
The kilowatt-hour (kWh) equals exactly 3,600,000 joules — the unit on every household electricity bill. One kWh runs a 1,000 W appliance for one hour.
Kilowatt-hours to Kilojoules Converter
1 kWh = 3600 kJ (kilowatt-hour → kilojoule)
1 kWh = 3600 kJ
1 kilowatt-hour equals 3600 kilojoules. To convert kilowatt-hours to kilojoules, multiply the kilowatt-hour value by 3600. For quick reference: 1 kWh = 3600 kJ, 5 kWh = 18000 kJ, 10 kWh = 36000 kJ, 100 kWh = 360000 kJ.
Formula
Kilojoules = Kilowatt-hours × 3600Quick
When to use kilowatt-hours → kilojoules
Kilowatt-hours to kilojoules multiplies by 3,600 exactly (1 kWh = 3,600,000 J). A 75 kWh electric-vehicle battery stores 270,000 kJ; a single kWh from the wall is 3,600 kJ, the energy of roughly 36 espresso shots at ~100 kJ each. This conversion moves billing-scale electrical figures into SI for engineering or thermodynamic work. Mind the sibling factor: kWh × 3.6 gives megajoules, kWh × 3,600 gives kilojoules — a mislabeled prefix is the usual failure mode.
Combined-heat-and-power plant operators comparing the electrical output of a generator, metered in kilowatt-hours, against the thermal energy content of the fuel burned, tabulated in kilojoules, use this conversion to compute overall plant efficiency. A generator producing 5.000 kWh of electricity corresponds to 18,000 kJ if converted at 100% efficiency — a benchmark operators then compare against the actual fuel kilojoules burned to find the real-world conversion efficiency, typically well under half for a conventional power station.
How to convert kilowatt-hours to kilojoules
Take your value
Start with your value in kilowatt-hours.
Multiply by 3600
Multiply the kilowatt-hour value by 3600. This is the exact conversion factor from kilowatt-hours to kilojoules.
Read the result
The product is your value in kilojoules. For example, 5 kWh × 3600 = 18000 kJ.
Conversion formula
The exact factor from kilowatt-hours to kilojoules is 3600.
Kilojoules = Kilowatt-hours × 3600
Kilowatt-hours to Kilojoules conversion table
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Kilowatt-hours (kWh) | Kilojoules (kJ) |
|---|---|
| 0.001 kWh | 3.6 kJ |
| 0.01 kWh | 36 kJ |
| 0.1 kWh | 360 kJ |
| 0.5 kWh | 1800 kJ |
| 1 kWh | 3600 kJ |
| 1.5 kWh | 5400 kJ |
| 2 kWh | 7200 kJ |
| 5 kWh | 18000 kJ |
| 10 kWh | 36000 kJ |
| 20 kWh | 72000 kJ |
| 50 kWh | 180000 kJ |
| 100 kWh | 360000 kJ |
| 200 kWh | 720000 kJ |
| 250 kWh | 900000 kJ |
| 500 kWh | 1800000 kJ |
| 1000 kWh | 3600000 kJ |
| 2000 kWh | 7200000 kJ |
| 2500 kWh | 9000000 kJ |
| 3600 kWh | 12960000 kJ |
| 5000 kWh | 18000000 kJ |
| 7500 kWh | 27000000 kJ |
| 10000 kWh | 36000000 kJ |
| 25000 kWh | 90000000 kJ |
| 50000 kWh | 180000000 kJ |
| 100000 kWh | 360000000 kJ |
| 250000 kWh | 900000000 kJ |
| 500000 kWh | 1800000000 kJ |
| 1000000 kWh | 3600000000 kJ |
| 2000000 kWh | 7200000000 kJ |
| 3600000 kWh | 12960000000 kJ |
| 5000000 kWh | 18000000000 kJ |
| 10000000 kWh | 36000000000 kJ |
| 25000000 kWh | 90000000000 kJ |
| 50000000 kWh | 180000000000 kJ |
| 100000000 kWh | 360000000000 kJ |
| 250000000 kWh | 900000000000 kJ |
| 500000000 kWh | 1800000000000 kJ |
| 1000000000 kWh | 3600000000000 kJ |
| 2000000000 kWh | 7200000000000 kJ |
| 5000000000 kWh | 18000000000000 kJ |
| 10000000000 kWh | 36000000000000 kJ |
| 20000000000 kWh | 72000000000000 kJ |
| 50000000000 kWh | 180000000000000 kJ |
| 100000000000 kWh | 360000000000000 kJ |
| 1000000000000 kWh | 3.6000 × 10^15 kJ |
| 10000000000000 kWh | 3.6000 × 10^16 kJ |
| 100000000000000 kWh | 3.6000 × 10^17 kJ |
| 1000000000000000 kWh | 3.6000 × 10^18 kJ |
| 10000000000000000 kWh | 3.6000 × 10^19 kJ |
| 100000000000000000 kWh | 3.6000 × 10^20 kJ |
Real-world reference
A US household uses about 30 kWh of electricity per day. A modern electric vehicle has a 50–100 kWh battery. In kilojoules, that gives you: 1 kWh = 3600 kJ, 10 kWh = 36000 kJ, 100 kWh = 360000 kJ.
Frequently asked questions
- How many kilojoules are in 1 kilowatt-hour?
- 1 kilowatt-hour equals 3600 kilojoules.
- How do I convert kilowatt-hours to kilojoules?
- Multiply the kilowatt-hour value by 3600. So x kWh × 3600 = the equivalent in kJ.
- What is 5 kilowatt-hours in kilojoules?
- 5 kilowatt-hours equals 18000 kilojoules.
- What is 10 kilowatt-hours in kilojoules?
- 10 kilowatt-hours equals 36000 kilojoules.
- What is 100 kilowatt-hours in kilojoules?
- 100 kilowatt-hours equals 360000 kilojoules.
- How do I convert back from kilojoules to kilowatt-hours?
- Multiply the kilojoule value by 0.000277778. For example, 1 kJ = 0.000277778 kWh.
- Is the kilowatt-hour bigger than the kilojoule?
- Yes. 1 kilowatt-hour is larger than 1 kilojoule — specifically 3600 times larger.
- Are these conversion factors exact?
- The factor is derived directly from the SI definitions of kilowatt-hour and kilojoule; the displayed value is rounded for readability, and the browser computes using IEEE 754 double-precision arithmetic.
About the kilowatt-hour and the kilojoule
The kilojoule
The kilojoule (kJ) equals exactly 1,000 joules. It is the standard unit on EU and many non-US nutrition labels — 1 dietary calorie ≈ 4.184 kJ. It also appears in industrial-process specifications and energy-storage ratings.