Gigajoules to Megawatt-hours Converter
Enter the energy in gigajoules below to convert it to megawatt-hours.
Convert Gigajoules to Megawatt-hours
Enter a value in gigajoules (GJ) to convert to megawatt-hours (MWh).
Gigajoule to Megawatt-hour Conversion Table
Table showing various gigajoule measurements converted to megawatt-hours. Click any preset value or arrow to load it into the converter.
| Gigajoules (GJ) | Megawatt-hours (MWh) |
|---|---|
| 1 GJ | 0.2777778 MWh |
| 2 GJ | 0.5555556 MWh |
| 2.5 GJ | 0.6944444 MWh |
| 5 GJ | 1.3888889 MWh |
| 10 GJ | 2.7777778 MWh |
| 15 GJ | 4.1666667 MWh |
| 20 GJ | 5.5555556 MWh |
| 25 GJ | 6.9444444 MWh |
| 30 GJ | 8.3333333 MWh |
| 50 GJ | 13.8888889 MWh |
How to Convert Gigajoules to Megawatt-hours
To convert gigajoules to megawatt-hours, multiply the energy by the following conversion ratio: 0.2777778 megawatt-hours/gigajoule.
Since one gigajoule is equal to 0.2777778 megawatt-hours, you can use this simple formula to convert:
The energy in megawatt-hours is equal to the energy in gigajoules multiplied by 0.2777778.
For example, here's how to convert 5 gigajoules to megawatt-hours using the formula above.
How Many Megawatt-hours Are in a Gigajoule?
There are 0.2777778 megawatt-hours in a gigajoule, which is why we use this value in the formula above.
Our gigajoule to megawatt-hour calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Gigajoules and megawatt-hours are both units used to measure energy. Keep reading to learn more about each unit.
What Is a Gigajoule?
A gigajoule is a unit of energy equal to 1,000,000,000 joules (J), the base unit for energy. Equal to 1,000,000,000 Joules, common in natural gas billing. [1]
The gigajoule is classified as an International System of Units (SI) unit of energy. Gigajoules can be abbreviated as GJ; for example, 1 gigajoule can be written as 1 GJ.
In the metric system, "giga" is the standard SI prefix for billions, or 10⁹. This makes the gigajoule (GJ) a convenient decimal multiple of the joule (J).
In practice, gigajoules (GJ) are widely used across large-scale industrial, bulk, and macro-level energy specifications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.
What Is a Megawatt-hour?
A megawatt-hour is a unit of energy equal to 3,600,000,000 joules (J), the base unit for energy. Equal to 1,000 kilowatt-hours (3.6 Gigajoules). [2]
The megawatt-hour is classified as a metric and SI-compatible unit of energy. Megawatt-hours can be abbreviated as MWh; for example, 1 megawatt-hour can be written as 1 MWh.
In the metric system, "mega" is the standard SI prefix for millions, or 10⁶. This makes the megawatt-hour (MWh) a convenient decimal multiple of the joule (J).
In practice, megawatt-hours (MWh) are widely used across large-scale industrial, bulk, and macro-level energy specifications within SI metric workflows, engineering documentation, and technical data sheets.
When converting energy between gigajoules (GJ) and megawatt-hours (MWh), keep full floating-point precision (1 GJ = 0.2777778 MWh; 1 MWh = 3.6 GJ) during intermediate calculations and round only the final megawatt-hour figure to match your instrument tolerance.
More Gigajoule & Megawatt-hour Conversions
Need to calculate in the opposite direction? Use our megawatt-hours to gigajoules calculator to switch your starting unit immediately. You can also explore related tools such as converting megawatt-hours to gigajoules, converting joules to calories, or converting calories to joules.
Convert from Gigajoules
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Gigajoules (GJ) to Megawatt-hours (MWh)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gigajoule (GJ) & Megawatt-hour (MWh)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (GJ to MWh)