Gigajoule is 1000000000 joule units.
Gigajoules to kWhs Converter — GJ to kWh
Convert Gigajoule (GJ) to kWh (kWh) using the exact conversion factor (1 gigajoule = 277.7777778 kwh). See the formula, worked examples, conversion table, history, and common uses.
Gigajoules to kWhs 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.
A kilowatt-hour is 3.6 million joules.
Result = input x 1e+9 / 3.6e+6.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Gigajoules to kWhs
Gigajoule and kWh both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Gigajoule is 1000000000 joule units, and a kilowatt-hour is 3.6 million joules.
Formula
kwhs = gigajoules × 277.777777778
This factor comes from each unit's defined relationship to the category's base unit: 1 gigajoule equals 1000000000 base units, and 1 kwh equals 3600000 base units, so dividing one by the other gives the direct gigajoule-to-kwh factor of 277.777777778.
Simple example
1 GJ × 277.7777778 = 277.7777778 kWh
1 gigajoule = 277.7777778 kwhs.
Real-world example
100 GJ × 277.7777778 = 27,777.77778 kWh
100 gigajoules = 27,777.77778 kwhs.
Conversion table
| Gigajoule (GJ) | kWh (kWh) |
|---|---|
| 1 GJ | 277.7777778 kWh |
| 10 GJ | 2,777.777778 kWh |
| 100 GJ | 27,777.77778 kWh |
| 500 GJ | 138,888.8889 kWh |
| 1,000 GJ | 277,777.7778 kWh |
| 2,000 GJ | 555,555.5556 kWh |
Reverse conversion: kWh to Gigajoule
277.7777778 kWh × 0.0036 = 1 GJ
277.7777778 kwhs = 1 gigajoules.
gigajoules = kwhs × 0.0036
For a page dedicated to this direction, see kWh to Gigajoule.
Understanding the Gigajoule (GJ)
Gigajoule is 1000000000 joule units.
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.
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 kwhs are in 1 gigajoule?
1 gigajoule equals 277.7777778 kwhs, using the exact defined conversion factor rather than an estimate.
How do I convert gigajoule to kwh?
Multiply the gigajoule value by 277.7777778. The converter above does this instantly to whatever precision you set.
How do I convert kwh back to gigajoule?
Use the reverse factor: 1 kwh equals 0.0036 gigajoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a gigajoule?
Gigajoule (GJ) is a unit of energy.
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.
Is the gigajoule to kwh 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.