Convert Kilowatt-hours to Joules
1 kilowatt-hour is 3,600,000 J. One kilowatt-hour is exactly 3600000 joules.
One kilowatt-hour is 3600000 joules. To convert kilowatt-hours to joules, multiply by 3600000; to go the other way, divide by 3600000 or multiply by 2.7778 × 10^-7. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousand watt-hours, and the unit every electricity bill is added up in.
Factor checked against the defining standard · How we check
- Kilowatt-hours × 3600000
value * 36000003,600,000 J
1 kilowatt-hour in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 3,600,000 J | × 3,600,000 |
| kilojoules | 3,600 kJ | × 3,600 |
| calories | 860,420.6501 cal | × 860,420.650096 |
| kilocalories | 860.4206501 kcal | × 860.420650096 |
| watt-hours | 1,000 Wh | × 1,000 |
| kilowatt-hours (as entered) | 1 kWh | — |
| British thermal units | 3,412.141633 BTU | × 3,412.14163313 |
| foot-pounds | 2,655,223.737 ft·lbf | × 2,655,223.7374 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert kilowatt-hours to joules?
- 1.Take the measurement in kilowatt-hours.
- 2.Multiply by 3600000 — that is how many joules fit in one kilowatt-hour.
- 3.To go back the other way, divide by 3600000, or multiply by 2.7778 × 10^-7.
Worked example: 25 kilowatt-hours to joules
- Formula
- kWh × 3600000 = J
- Arithmetic
- 25 × 3600000 = 90,000,000 J
- Answer
- 25 kWh = 90,000,000 J
The factor is exact, so this figure is exact too — only the display is rounded.
Kilowatt-hours to joules conversion table
| Kilowatt-hours | Joules |
|---|---|
| 1 kWh | 3,600,000 J |
| 2 kWh | 7,200,000 J |
| 3 kWh | 10,800,000 J |
| 4 kWh | 14,400,000 J |
| 5 kWh | 18,000,000 J |
| 6 kWh | 21,600,000 J |
| 7 kWh | 25,200,000 J |
| 8 kWh | 28,800,000 J |
| 9 kWh | 32,400,000 J |
| 10 kWh | 36,000,000 J |
| 12 kWh | 43,200,000 J |
| 15 kWh | 54,000,000 J |
| 20 kWh | 72,000,000 J |
| 25 kWh | 90,000,000 J |
| 50 kWh | 180,000,000 J |
| 100 kWh | 360,000,000 J |
| 200 kWh | 720,000,000 J |
| 300 kWh | 1,080,000,000 J |
| 500 kWh | 1,800,000,000 J |
| 1000 kWh | 3,600,000,000 J |
| 2000 kWh | 7,200,000,000 J |
| 5000 kWh | 18,000,000,000 J |
| 10000 kWh | 36,000,000,000 J |
What is a kilowatt-hour?
A thousand watt-hours, and the unit every electricity bill is added up in. Exactly 3.6 megajoules, and the reason a 100 W bulb left on for ten hours costs one unit.
What is a joule?
The SI unit: one newton acting through one metre. Dropping a small apple one metre releases about one joule.
How many joules are in a kilowatt-hour?
One kilowatt-hour is 3600000 joules, exactly. Going the other way, one joule is 2.7778 × 10^-7 kilowatt-hours. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every energy unit here
| Unit | Symbol | One of these is |
|---|---|---|
| Joules | J | the base unit |
| Kilojoules | kJ | 1000 joule |
| Calories | cal | 4.184 joule |
| Kilocalories | kcal | 4184 joule |
| Watt-hours | Wh | 3600 joule |
| Kilowatt-hours | kWh | 3600000 joule |
| British thermal units | BTU | 1055.0559 joule |
| Foot-pounds | ft·lbf | 1.3558179 joule |
Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J
Questions people actually ask
- How many joules are in a kilowatt-hour?
- 3600000. The SI unit: one newton acting through one metre. Dropping a small apple one metre releases about one joule.
- How do I convert joules back to kilowatt-hours?
- Divide by 3600000, or multiply by 2.7778 × 10^-7 — they are the same operation.
Other energy conversions
Joules to kilowatt-hours — the same conversion the other way.