Gigajoules to Calories Converter
Enter the energy in gigajoules below to convert it to calories.
Convert Gigajoules to Calories
Enter a value in gigajoules (GJ) to convert to calories (cal).
Gigajoule to Gram Calorie Conversion Table
Table showing various gigajoule measurements converted to calories. Click any preset value or arrow to load it into the converter.
| Gigajoules (GJ) | Calories (cal) |
|---|---|
| 0.0000001 GJ | 23.9005736 cal |
| 0.0000002 GJ | 47.8011472 cal |
| 0.0000003 GJ | 71.7017208 cal |
| 0.0000004 GJ | 95.6022945 cal |
| 0.0000005 GJ | 119.5028681 cal |
| 0.0000006 GJ | 143.4034417 cal |
| 0.0000007 GJ | 167.3040153 cal |
| 0.0000008 GJ | 191.2045889 cal |
| 0.0000009 GJ | 215.1051625 cal |
| 0.00000001 GJ | 2.3900574 cal |
How to Convert Gigajoules to Calories
To convert gigajoules to calories, multiply the energy by the following conversion ratio: 239,005,736.1376673 calories/gigajoule.
Since one gigajoule is equal to 239,005,736.1376673 calories, you can use this simple formula to convert:
The energy in calories is equal to the energy in gigajoules multiplied by 239,005,736.1376673.
For example, here's how to convert 5 gigajoules to calories using the formula above.
How Many Calories Are in a Gigajoule?
There are 239,005,736.1376673 calories in a gigajoule, which is why we use this value in the formula above.
Our gigajoule to gram calorie calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Gigajoules and calories 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 Gram Calorie?
A gram calorie is a unit of energy equal to 4.184 joules (J), the base unit for energy. Thermochemical gram calorie defined as 4.184 Joules. [2]
The gram calorie is classified as a standard unit of energy. Calories can be abbreviated as cal; for example, 1 gram calorie can be written as 1 cal.
When working with calories (cal) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, calories (cal) are widely used across standard energy applications within international standard workflows, engineering documentation, and technical data sheets.
When converting energy between gigajoules (GJ) and calories (cal), keep full floating-point precision (1 GJ = 239,005,736.1376673 cal; 1 cal = 4.184e-9 GJ) during intermediate calculations and round only the final gram calorie figure to match your instrument tolerance.
More Gigajoule & Gram Calorie Conversions
Need to calculate in the opposite direction? Use our calories to gigajoules calculator to switch your starting unit immediately. You can also explore related tools such as converting calories 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 Calories (cal)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gigajoule (GJ) & Gram Calorie (cal) (cal)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (GJ to cal)