Gigajoules to Watt-hours Converter
Enter the energy in gigajoules below to convert it to watt-hours.
Convert Gigajoules to Watt-hours
Enter a value in gigajoules (GJ) to convert to watt-hours (Wh).
Gigajoule to Watt-hour Conversion Table
Table showing various gigajoule measurements converted to watt-hours. Click any preset value or arrow to load it into the converter.
| Gigajoules (GJ) | Watt-hours (Wh) |
|---|---|
| 0.0000001 GJ | 0.0277778 Wh |
| 0.0000002 GJ | 0.0555556 Wh |
| 0.0000003 GJ | 0.0833333 Wh |
| 0.0000004 GJ | 0.1111111 Wh |
| 0.0000005 GJ | 0.1388889 Wh |
| 0.0000006 GJ | 0.1666667 Wh |
| 0.0000007 GJ | 0.1944444 Wh |
| 0.0000008 GJ | 0.2222222 Wh |
| 0.0000009 GJ | 0.25 Wh |
| 0.00000001 GJ | 0.0027778 Wh |
How to Convert Gigajoules to Watt-hours
To convert gigajoules to watt-hours, multiply the energy by the following conversion ratio: 277,777.7777778 watt-hours/gigajoule.
Since one gigajoule is equal to 277,777.7777778 watt-hours, you can use this simple formula to convert:
The energy in watt-hours is equal to the energy in gigajoules multiplied by 277,777.7777778.
For example, here's how to convert 5 gigajoules to watt-hours using the formula above.
How Many Watt-hours Are in a Gigajoule?
There are 277,777.7777778 watt-hours in a gigajoule, which is why we use this value in the formula above.
Our gigajoule to watt-hour calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Gigajoules and watt-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 Watt-hour?
A watt-hour is a unit of energy equal to 3,600 joules (J), the base unit for energy. Equal to 3,600 Joules. [2]
The watt-hour is classified as a metric and SI-compatible unit of energy. Watt-hours can be abbreviated as Wh; for example, 1 watt-hour can be written as 1 Wh.
When working with watt-hours (Wh) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, watt-hours (Wh) 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 watt-hours (Wh), keep full floating-point precision (1 GJ = 277,777.7777778 Wh; 1 Wh = 0.0000036 GJ) during intermediate calculations and round only the final watt-hour figure to match your instrument tolerance.
More Gigajoule & Watt-hour Conversions
Need to calculate in the opposite direction? Use our watt-hours to gigajoules calculator to switch your starting unit immediately. You can also explore related tools such as converting watt-hours to gigajoules, converting ampere-hours to watt-hours, or converting milliampere-hours to watt-hours.
Convert from Gigajoules
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Gigajoules (GJ) to Watt-hours (Wh)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gigajoule (GJ) & Watt-hour (Wh)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (GJ to Wh)