Kilojoules to Watt-hours (kJ to Wh) Converter
1 kilojoule equals 0.27777778 watt-hours — multiply the number of kilojoules by 0.27777778 to convert to watt-hours. Because 1 Wh is 3600 joules (3.6 kJ), the factor is 1000 divided by 3600.
The formula
To convert kilojoules to watt-hours, multiply by 0.27777778:
watt-hours = kilojoules × 0.27777778
For example, 3.6 kJ × 0.27777778 = 1 Wh. The reverse factor is 1 Wh = 3.6 kJ.
Conversion table
| Kilojoules (kJ) | Watt-hours (Wh) |
|---|---|
| 1 | 0.277778 |
| 2 | 0.555556 |
| 5 | 1.388889 |
| 10 | 2.777778 |
| 25 | 6.944444 |
| 50 | 13.888889 |
| 100 | 27.777778 |
| 500 | 138.888889 |
| 1000 | 277.777778 |
How to convert online
- Type the number of kilojoules into the first box.
- Read the equivalent watt-hours instantly in the second box.
- Or enter a watt-hour value to convert back to kilojoules — it works both ways.
Use the Kilojoule to Watt-hour Converter — free and instant in your browser.
Where this conversion is used
Watt-hours rate small batteries, power banks, laptops and solar storage, while energy specs and physics data often come in kilojoules. Converting kJ to Wh helps compare a stated energy amount against battery capacity, size a portable power supply, or check how much a device can store and deliver.
FAQ
How many watt-hours are in a kilojoule?
0.27777778 Wh. So 100 kJ = 27.777778 Wh, and 3.6 kJ = 1 Wh.
What is the formula to convert kilojoules to watt-hours?
Wh = kJ × 0.27777778, which is the same as dividing kilojoules by 3.6.
How do I convert watt-hours back to kilojoules?
Multiply by 3.6. For example, 50 Wh = 180 kJ.
Is the conversion exact?
The exact factor is 1000/3600 ≈ 0.277778; the tool applies it to high precision.
Related converters
- Watt-hour to Kilojoule Converter
- Kilojoule to Kilowatt-hour Converter
- Kilojoule to Joule Converter
- Kilojoule to Kilocalorie Converter
Built by ByteVancer
ByteTools is a free product of ByteVancer, a software and web development studio. Need a custom energy or battery tool? ByteVancer builds fast, privacy-first web apps.
Recommended reading
Watt-hour to Kilowatt-hour (Wh to kWh) Converter
1 watt-hour equals 0.001 kilowatt-hours. Divide by 1000 to convert Wh to kWh, with the exact formula and a handy reference table.
Watt-hour to Kilojoule (Wh to kJ) Converter
1 watt-hour equals 3.6 kilojoules exactly. Use the formula, an easy factor and a reference table to convert Wh to kJ instantly and free.
Watt-hour to Kilocalorie (Wh to kcal) Converter
1 watt-hour equals 0.86042065 kilocalories. Use the exact factor, formula and a reference table to convert Wh to kcal fast and free.
Watt-hour to Joule Converter (Wh to J) + Formula
1 watt-hour equals 3,600 joules. Convert Wh to joules with the exact factor, a simple formula, and a reference table of common values.