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Gigajoules to Attojoules Converter

Enter the energy in gigajoules below to convert it to attojoules.

Convert Gigajoules to Attojoules

Enter a value in gigajoules (GJ) to convert to attojoules (aJ).

Result
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5e+27attojoules
5 GJ = 5e+27 aJ
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Reference:NIST CODATA (CODATA Energy & Thermodynamic Constants)
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Gigajoule to Attojoule Conversion Table

Table showing various gigajoule measurements converted to attojoules. Click any preset value or arrow to load it into the converter.

Gigajoules (GJ)Attojoules (aJ)
0.0000001 GJ1e+20 aJ
0.0000002 GJ2e+20 aJ
0.0000003 GJ3e+20 aJ
0.0000004 GJ4e+20 aJ
0.0000005 GJ5e+20 aJ
0.0000006 GJ6e+20 aJ
0.0000007 GJ7e+20 aJ
0.0000008 GJ8e+20 aJ
0.0000009 GJ9e+20 aJ
0.00000001 GJ1e+19 aJ

How to Convert Gigajoules to Attojoules

To convert gigajoules to attojoules, multiply the energy by the following conversion ratio: 1e+27 attojoules/gigajoule.

Since one gigajoule is equal to 1e+27 attojoules, you can use this simple formula to convert:

attojoules = gigajoules × 1e+27

The energy in attojoules is equal to the energy in gigajoules multiplied by 1e+27.

For example, here's how to convert 5 gigajoules to attojoules using the formula above.

attojoules = (5 GJ × 1e+27) = 5e+27 aJ

How Many Attojoules Are in a Gigajoule?

There are 1e+27 attojoules in a gigajoule, which is why we use this value in the formula above.

1 GJ = 1e+27 aJ|1 aJ = 1e-27 GJ

Our gigajoule to attojoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Gigajoules and attojoules 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 an Attojoule?

An attojoule is a unit of energy equal to 1/999,999,999,999,999,900 of a joule (1e-18 J). 10⁻¹⁸ Joules. [2]

The attojoule is classified as a metric and SI-compatible unit of energy. Attojoules can be abbreviated as aJ; for example, 1 attojoule can be written as 1 aJ.

When working with attojoules (aJ) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, attojoules (aJ) are widely used across fine-tolerance laboratory, analytical, and micro-scale energy measurements within SI metric workflows, engineering documentation, and technical data sheets.

When converting energy between gigajoules (GJ) and attojoules (aJ), keep full floating-point precision (1 GJ = 1e+27 aJ; 1 aJ = 1e-27 GJ) during intermediate calculations and round only the final attojoule figure to match your instrument tolerance.

More Gigajoule & Attojoule Conversions

Need to calculate in the opposite direction? Use our attojoules to gigajoules calculator to switch your starting unit immediately. You can also explore related tools such as converting attojoules to gigajoules, converting joules to calories, or converting calories to joules.

Frequently Asked Questions

There are 1.000000e+27 attojoules (aJ) in 1 gigajoule (GJ). Conversely, 1 attojoule (aJ) is equal to 1.000000e-27 gigajoules (GJ).

References

NIST · BIPM · ISO
  1. [1]
    NIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Gigajoules (GJ) to Attojoules (aJ)
    NIST CODATA Standard
  2. [2]
    NIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gigajoule (GJ) & Attojoule (aJ)
    NIST SP 811 Specification
  3. [3]
    BIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (GJ to aJ)
    BIPM Reference
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