Energy converter
Kilowatt-hours to Joules
Converting Kilowatt-hours to Joules is a single multiplication when you know the factor. One kWh equals 3,600,000 J, so multiply the value in kWh by 3,600,000. The calculator below works in both directions and accepts decimals.
Formula 1 kWh = 3,600,000 J
Need the other direction? Joules to Kilowatt-hours.
How to convert Kilowatt-hours to Joules
A kilowatt-hour is 3.6 megajoules and is the unit on electricity bills. The joule is the SI unit of energy, equal to one newton-metre.
To convert Kilowatt-hours to Joules, multiply the value in kWh by 3,600,000. For example, 10 kWh × 3,600,000 = 36,000,000 J. This works because the ratio between the two units is constant for every value in energy.
Worked examples
| kWh | J |
|---|---|
| 1 kWh | 3,600,000 J |
| 2.5 kWh | 9,000,000 J |
| 5 kWh | 18,000,000 J |
| 10 kWh | 36,000,000 J |
| 25 kWh | 90,000,000 J |
| 50 kWh | 180,000,000 J |
| 100 kWh | 360,000,000 J |
Reverse conversion
| J | kWh |
|---|---|
| 1 J | 2.7778e-07 kWh |
| 5 J | 1.3889e-06 kWh |
| 10 J | 2.7778e-06 kWh |
| 25 J | 6.9444e-06 kWh |
| 50 J | 1.3889e-05 kWh |
| 100 J | 2.7778e-05 kWh |
When this conversion is useful
This is the calculation you need when you are comparing a nutrition label, an electricity bill or a heating system. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 kWh is 3,600,000,000 J.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
kWh to J conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Kilowatt-hours (kWh) | Joules (J) |
|---|---|
| 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 |
| 11 kWh | 39,600,000 J |
| 12 kWh | 43,200,000 J |
| 13 kWh | 46,800,000 J |
| 14 kWh | 50,400,000 J |
| 15 kWh | 54,000,000 J |
| 16 kWh | 57,600,000 J |
| 17 kWh | 61,200,000 J |
| 18 kWh | 64,800,000 J |
| 19 kWh | 68,400,000 J |
| 20 kWh | 72,000,000 J |
| 21 kWh | 75,600,000 J |
| 22 kWh | 79,200,000 J |
| 23 kWh | 82,800,000 J |
| 24 kWh | 86,400,000 J |
| 25 kWh | 90,000,000 J |
| 26 kWh | 93,600,000 J |
| 27 kWh | 97,200,000 J |
| 28 kWh | 100,800,000 J |
| 29 kWh | 104,400,000 J |
| 30 kWh | 108,000,000 J |
| 31 kWh | 111,600,000 J |
| 32 kWh | 115,200,000 J |
| 33 kWh | 118,800,000 J |
| 34 kWh | 122,400,000 J |
| 35 kWh | 126,000,000 J |
| 36 kWh | 129,600,000 J |
| 37 kWh | 133,200,000 J |
| 38 kWh | 136,800,000 J |
| 39 kWh | 140,400,000 J |
| 40 kWh | 144,000,000 J |
| 41 kWh | 147,600,000 J |
| 42 kWh | 151,200,000 J |
| 43 kWh | 154,800,000 J |
| 44 kWh | 158,400,000 J |
| 45 kWh | 162,000,000 J |
| 46 kWh | 165,600,000 J |
| 47 kWh | 169,200,000 J |
| 48 kWh | 172,800,000 J |
| 49 kWh | 176,400,000 J |
| 50 kWh | 180,000,000 J |
| 60 kWh | 216,000,000 J |
| 70 kWh | 252,000,000 J |
| 80 kWh | 288,000,000 J |
| 90 kWh | 324,000,000 J |
| 100 kWh | 360,000,000 J |
Frequently asked questions
How many Joules are in 1 Kilowatt-hours?
1 kWh equals 3,600,000 J.
How do I convert Kilowatt-hours to Joules?
Multiply the kWh value by 3,600,000. Example: 25 kWh = 90,000,000 J.
What is 2.5 kWh in J?
2.5 kWh = 9,000,000 J.
Is the kWh to J conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.